An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk...
Transcript of An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk...
![Page 1: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/1.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
An Analytic Grothendieck Riemann RochTheorem
Xiang Tang
Washington University in St. Louis
March 26, 2019
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 2: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/2.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Outline
In this talk, we will discuss an index problem arising fromfunctional analysis, i.e. the Arveson-Douglas conjecture.We will present some recent progress in the study of thisindex problem.
This is a fundamental and beautiful problem connected tomany different branches of Mathematics. We would like totake this opportunity to encourage our audience to join ourjourney of exploring this problem.
This talk is based on joint work with R. Douglas, M.Jabbari, and G. Yu.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 3: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/3.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Outline
In this talk, we will discuss an index problem arising fromfunctional analysis, i.e. the Arveson-Douglas conjecture.We will present some recent progress in the study of thisindex problem.
This is a fundamental and beautiful problem connected tomany different branches of Mathematics. We would like totake this opportunity to encourage our audience to join ourjourney of exploring this problem.
This talk is based on joint work with R. Douglas, M.Jabbari, and G. Yu.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 4: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/4.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Outline
In this talk, we will discuss an index problem arising fromfunctional analysis, i.e. the Arveson-Douglas conjecture.We will present some recent progress in the study of thisindex problem.
This is a fundamental and beautiful problem connected tomany different branches of Mathematics. We would like totake this opportunity to encourage our audience to join ourjourney of exploring this problem.
This talk is based on joint work with R. Douglas, M.Jabbari, and G. Yu.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 5: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/5.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Outline
In this talk, we will discuss an index problem arising fromfunctional analysis, i.e. the Arveson-Douglas conjecture.We will present some recent progress in the study of thisindex problem.
This is a fundamental and beautiful problem connected tomany different branches of Mathematics. We would like totake this opportunity to encourage our audience to join ourjourney of exploring this problem.
This talk is based on joint work with R. Douglas, M.Jabbari, and G. Yu.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 6: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/6.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
1 Toeplitz Index TheoremToeplitz operators on the unit diskToeplitz operators on the ball
2 Arveson-Douglas ConjectureEssential normalityGeometry and an index problem
3 Recent ProgressRadical caseNon-radical caseBeyond topology
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 7: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/7.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
Table of Contents
1 Toeplitz Index TheoremToeplitz operators on the unit diskToeplitz operators on the ball
2 Arveson-Douglas ConjectureEssential normalityGeometry and an index problem
3 Recent ProgressRadical caseNon-radical caseBeyond topology
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 8: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/8.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
Unit disk
Let D be the unit disk in the complex plane C.
Let L2a(D) be the Hilbert space of square integrable analytic
functions on D with respect to the Lebesgue measure.Let z be the coordinate function on C.Consider the Toeplitz operator Tz : L2
a(D)→ L2a(D) by
Tz(ξ) := zξ.
Proposition
The kernel of the operator Tz is trivial. The cokernel of Tz, i.e.ker(T ∗z ), is spanned by the constant function 1 in L2
a(D).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 9: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/9.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
Unit disk
Let D be the unit disk in the complex plane C.Let L2
a(D) be the Hilbert space of square integrable analyticfunctions on D with respect to the Lebesgue measure.
Let z be the coordinate function on C.Consider the Toeplitz operator Tz : L2
a(D)→ L2a(D) by
Tz(ξ) := zξ.
Proposition
The kernel of the operator Tz is trivial. The cokernel of Tz, i.e.ker(T ∗z ), is spanned by the constant function 1 in L2
a(D).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 10: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/10.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
Unit disk
Let D be the unit disk in the complex plane C.Let L2
a(D) be the Hilbert space of square integrable analyticfunctions on D with respect to the Lebesgue measure.Let z be the coordinate function on C.
Consider the Toeplitz operator Tz : L2a(D)→ L2
a(D) by
Tz(ξ) := zξ.
Proposition
The kernel of the operator Tz is trivial. The cokernel of Tz, i.e.ker(T ∗z ), is spanned by the constant function 1 in L2
a(D).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 11: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/11.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
Unit disk
Let D be the unit disk in the complex plane C.Let L2
a(D) be the Hilbert space of square integrable analyticfunctions on D with respect to the Lebesgue measure.Let z be the coordinate function on C.Consider the Toeplitz operator Tz : L2
a(D)→ L2a(D) by
Tz(ξ) := zξ.
Proposition
The kernel of the operator Tz is trivial. The cokernel of Tz, i.e.ker(T ∗z ), is spanned by the constant function 1 in L2
a(D).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 12: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/12.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
Unit disk
Let D be the unit disk in the complex plane C.Let L2
a(D) be the Hilbert space of square integrable analyticfunctions on D with respect to the Lebesgue measure.Let z be the coordinate function on C.Consider the Toeplitz operator Tz : L2
a(D)→ L2a(D) by
Tz(ξ) := zξ.
Proposition
The kernel of the operator Tz is trivial.
The cokernel of Tz, i.e.ker(T ∗z ), is spanned by the constant function 1 in L2
a(D).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 13: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/13.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
Unit disk
Let D be the unit disk in the complex plane C.Let L2
a(D) be the Hilbert space of square integrable analyticfunctions on D with respect to the Lebesgue measure.Let z be the coordinate function on C.Consider the Toeplitz operator Tz : L2
a(D)→ L2a(D) by
Tz(ξ) := zξ.
Proposition
The kernel of the operator Tz is trivial. The cokernel of Tz, i.e.ker(T ∗z ), is spanned by the constant function 1 in L2
a(D).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 14: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/14.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
Fredholm Index
Operators with finite dimensional kernel an cokernel are calledFredholm operators.
Example
The operator Tz is a Fredholm operator.
The most important invariant associated to a Fredholmoperator T is called the Fredholm index,
ind(T ) := dim(
ker(T ))− dim
(coker(T )
).
Example
ind(Tz) = −1.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 15: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/15.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
Fredholm Index
Operators with finite dimensional kernel an cokernel are calledFredholm operators.
Example
The operator Tz is a Fredholm operator.
The most important invariant associated to a Fredholmoperator T is called the Fredholm index,
ind(T ) := dim(
ker(T ))− dim
(coker(T )
).
Example
ind(Tz) = −1.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 16: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/16.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
Fredholm Index
Operators with finite dimensional kernel an cokernel are calledFredholm operators.
Example
The operator Tz is a Fredholm operator.
The most important invariant associated to a Fredholmoperator T is called the Fredholm index,
ind(T ) := dim(
ker(T ))− dim
(coker(T )
).
Example
ind(Tz) = −1.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 17: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/17.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
Fredholm Index
Operators with finite dimensional kernel an cokernel are calledFredholm operators.
Example
The operator Tz is a Fredholm operator.
The most important invariant associated to a Fredholmoperator T is called the Fredholm index,
ind(T ) := dim(
ker(T ))− dim
(coker(T )
).
Example
ind(Tz) = −1.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 18: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/18.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
Toeplitz index
The dimension of ker(T ) may change with small perturbations,but the Fredholm index ind(T ) stays constant with respect tocontinuous variations.
Let f be a continuous function on D. Define
Tf : L2a(D)→ L2
a(D), Tf (ξ) := S(fξ),
where S : L2(D)→ L2a(D) is the orthogonal projection to the
closed subspace L2a(D) ⊂ L2(D).
Theorem
1 Tf : L2a(D)→ L2
a(D) is Fredholm if and only if f |∂D isinvertible ;
2 When Tf is Fredholm, ind(Tf ) is
−wind(f |∂D : S1 → C∗
).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 19: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/19.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
Toeplitz index
The dimension of ker(T ) may change with small perturbations,but the Fredholm index ind(T ) stays constant with respect tocontinuous variations.Let f be a continuous function on D.
Define
Tf : L2a(D)→ L2
a(D), Tf (ξ) := S(fξ),
where S : L2(D)→ L2a(D) is the orthogonal projection to the
closed subspace L2a(D) ⊂ L2(D).
Theorem
1 Tf : L2a(D)→ L2
a(D) is Fredholm if and only if f |∂D isinvertible ;
2 When Tf is Fredholm, ind(Tf ) is
−wind(f |∂D : S1 → C∗
).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 20: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/20.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
Toeplitz index
The dimension of ker(T ) may change with small perturbations,but the Fredholm index ind(T ) stays constant with respect tocontinuous variations.Let f be a continuous function on D. Define
Tf : L2a(D)→ L2
a(D), Tf (ξ) := S(fξ),
where S : L2(D)→ L2a(D) is the orthogonal projection to the
closed subspace L2a(D) ⊂ L2(D).
Theorem
1 Tf : L2a(D)→ L2
a(D) is Fredholm if and only if f |∂D isinvertible ;
2 When Tf is Fredholm, ind(Tf ) is
−wind(f |∂D : S1 → C∗
).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 21: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/21.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
Toeplitz index
The dimension of ker(T ) may change with small perturbations,but the Fredholm index ind(T ) stays constant with respect tocontinuous variations.Let f be a continuous function on D. Define
Tf : L2a(D)→ L2
a(D), Tf (ξ) := S(fξ),
where S : L2(D)→ L2a(D) is the orthogonal projection to the
closed subspace L2a(D) ⊂ L2(D).
Theorem
1 Tf : L2a(D)→ L2
a(D) is Fredholm if and only if f |∂D isinvertible ;
2 When Tf is Fredholm, ind(Tf ) is
−wind(f |∂D : S1 → C∗
).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 22: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/22.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
Extension and K-homology
Proposition
The commutator [Tz, T∗z ] is a compact operator on L2
a(D).
Let K(L2a(D)) be the algebra of compact operators on
L2a(D).
Let T (D) be the closed ∗-subalgebra of B(L2a(D)
)generated by Tz and K(L2
a(D)) with respect to the operatornorm topology.Let C(S1) be the algebra of continuous functions onS1 = ∂D.
We have the following short exact sequence,
0 −→ K(L2a(D)) −→ T (D) −→ C(S1) −→ 0.
The above extension defines a K-homology class [T (D)] inK1(S1).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 23: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/23.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
Extension and K-homology
Proposition
The commutator [Tz, T∗z ] is a compact operator on L2
a(D).
Let K(L2a(D)) be the algebra of compact operators on
L2a(D).
Let T (D) be the closed ∗-subalgebra of B(L2a(D)
)generated by Tz and K(L2
a(D)) with respect to the operatornorm topology.Let C(S1) be the algebra of continuous functions onS1 = ∂D.
We have the following short exact sequence,
0 −→ K(L2a(D)) −→ T (D) −→ C(S1) −→ 0.
The above extension defines a K-homology class [T (D)] inK1(S1).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 24: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/24.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
Extension and K-homology
Proposition
The commutator [Tz, T∗z ] is a compact operator on L2
a(D).
Let K(L2a(D)) be the algebra of compact operators on
L2a(D).
Let T (D) be the closed ∗-subalgebra of B(L2a(D)
)generated by Tz and K(L2
a(D)) with respect to the operatornorm topology.
Let C(S1) be the algebra of continuous functions onS1 = ∂D.
We have the following short exact sequence,
0 −→ K(L2a(D)) −→ T (D) −→ C(S1) −→ 0.
The above extension defines a K-homology class [T (D)] inK1(S1).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 25: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/25.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
Extension and K-homology
Proposition
The commutator [Tz, T∗z ] is a compact operator on L2
a(D).
Let K(L2a(D)) be the algebra of compact operators on
L2a(D).
Let T (D) be the closed ∗-subalgebra of B(L2a(D)
)generated by Tz and K(L2
a(D)) with respect to the operatornorm topology.Let C(S1) be the algebra of continuous functions onS1 = ∂D.
We have the following short exact sequence,
0 −→ K(L2a(D)) −→ T (D) −→ C(S1) −→ 0.
The above extension defines a K-homology class [T (D)] inK1(S1).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 26: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/26.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
Extension and K-homology
Proposition
The commutator [Tz, T∗z ] is a compact operator on L2
a(D).
Let K(L2a(D)) be the algebra of compact operators on
L2a(D).
Let T (D) be the closed ∗-subalgebra of B(L2a(D)
)generated by Tz and K(L2
a(D)) with respect to the operatornorm topology.Let C(S1) be the algebra of continuous functions onS1 = ∂D.
We have the following short exact sequence,
0 −→ K(L2a(D)) −→ T (D) −→ C(S1) −→ 0.
The above extension defines a K-homology class [T (D)] inK1(S1).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 27: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/27.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
Extension and K-homology
Proposition
The commutator [Tz, T∗z ] is a compact operator on L2
a(D).
Let K(L2a(D)) be the algebra of compact operators on
L2a(D).
Let T (D) be the closed ∗-subalgebra of B(L2a(D)
)generated by Tz and K(L2
a(D)) with respect to the operatornorm topology.Let C(S1) be the algebra of continuous functions onS1 = ∂D.
We have the following short exact sequence,
0 −→ K(L2a(D)) −→ T (D) −→ C(S1) −→ 0.
The above extension defines a K-homology class [T (D)] inK1(S1).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 28: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/28.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
The Atiyah-Singer index theorem
And an invertible function f in C(S1) defines an element [f ] inK1(S1).
The Fredholm index ind(Tf ) can be interpreted as the pairing,
ind(Tf ) = 〈[T (D)], [f ]〉 .
The operator 1√−1
ddθ is an elliptic differential operator on S1 of
order 1. It also defines an element in K1(S1).
Theorem (Baum-Douglas)
In K1(S1), [T (D)] = [ 1√−1
ddθ ].
Corollary (Atiyah-Singer)
〈[T (D)], [f ]〉=〈[ 1√−1
ddθ ], [f ]〉 = ind(Tf ) = −wind(f |∂D).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 29: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/29.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
The Atiyah-Singer index theorem
And an invertible function f in C(S1) defines an element [f ] inK1(S1).The Fredholm index ind(Tf ) can be interpreted as the pairing,
ind(Tf ) = 〈[T (D)], [f ]〉 .
The operator 1√−1
ddθ is an elliptic differential operator on S1 of
order 1. It also defines an element in K1(S1).
Theorem (Baum-Douglas)
In K1(S1), [T (D)] = [ 1√−1
ddθ ].
Corollary (Atiyah-Singer)
〈[T (D)], [f ]〉=〈[ 1√−1
ddθ ], [f ]〉 = ind(Tf ) = −wind(f |∂D).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 30: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/30.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
The Atiyah-Singer index theorem
And an invertible function f in C(S1) defines an element [f ] inK1(S1).The Fredholm index ind(Tf ) can be interpreted as the pairing,
ind(Tf ) = 〈[T (D)], [f ]〉 .
The operator 1√−1
ddθ is an elliptic differential operator on S1 of
order 1. It also defines an element in K1(S1).
Theorem (Baum-Douglas)
In K1(S1), [T (D)] = [ 1√−1
ddθ ].
Corollary (Atiyah-Singer)
〈[T (D)], [f ]〉=〈[ 1√−1
ddθ ], [f ]〉 = ind(Tf ) = −wind(f |∂D).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 31: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/31.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
The Atiyah-Singer index theorem
And an invertible function f in C(S1) defines an element [f ] inK1(S1).The Fredholm index ind(Tf ) can be interpreted as the pairing,
ind(Tf ) = 〈[T (D)], [f ]〉 .
The operator 1√−1
ddθ is an elliptic differential operator on S1 of
order 1. It also defines an element in K1(S1).
Theorem (Baum-Douglas)
In K1(S1), [T (D)] = [ 1√−1
ddθ ].
Corollary (Atiyah-Singer)
〈[T (D)], [f ]〉=〈[ 1√−1
ddθ ], [f ]〉 = ind(Tf ) = −wind(f |∂D).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 32: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/32.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
The Atiyah-Singer index theorem
And an invertible function f in C(S1) defines an element [f ] inK1(S1).The Fredholm index ind(Tf ) can be interpreted as the pairing,
ind(Tf ) = 〈[T (D)], [f ]〉 .
The operator 1√−1
ddθ is an elliptic differential operator on S1 of
order 1. It also defines an element in K1(S1).
Theorem (Baum-Douglas)
In K1(S1), [T (D)] = [ 1√−1
ddθ ].
Corollary (Atiyah-Singer)
〈[T (D)], [f ]〉=〈[ 1√−1
ddθ ], [f ]〉 = ind(Tf ) = −wind(f |∂D).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 33: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/33.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
Unit ball
Let Bm be the unit ball in the complex plane Cm.
Let L2a(Bm) be the Hilbert space of square integrable analytic
functions on Bm with respect to the Lebesgue measure.Let z1, · · · , zm be the coordinate function on Cm.Consider the Toeplitz operator Tzi : L2
a(Bm)→ L2a(Bm) by
Tzi(ξ) := ziξ.
Proposition
The commutators
[Tzi , T∗zj ], i, j = 1, ...,m,
are compact operators on L2a(Bm).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 34: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/34.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
Unit ball
Let Bm be the unit ball in the complex plane Cm.Let L2
a(Bm) be the Hilbert space of square integrable analyticfunctions on Bm with respect to the Lebesgue measure.
Let z1, · · · , zm be the coordinate function on Cm.Consider the Toeplitz operator Tzi : L2
a(Bm)→ L2a(Bm) by
Tzi(ξ) := ziξ.
Proposition
The commutators
[Tzi , T∗zj ], i, j = 1, ...,m,
are compact operators on L2a(Bm).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 35: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/35.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
Unit ball
Let Bm be the unit ball in the complex plane Cm.Let L2
a(Bm) be the Hilbert space of square integrable analyticfunctions on Bm with respect to the Lebesgue measure.Let z1, · · · , zm be the coordinate function on Cm.
Consider the Toeplitz operator Tzi : L2a(Bm)→ L2
a(Bm) by
Tzi(ξ) := ziξ.
Proposition
The commutators
[Tzi , T∗zj ], i, j = 1, ...,m,
are compact operators on L2a(Bm).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 36: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/36.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
Unit ball
Let Bm be the unit ball in the complex plane Cm.Let L2
a(Bm) be the Hilbert space of square integrable analyticfunctions on Bm with respect to the Lebesgue measure.Let z1, · · · , zm be the coordinate function on Cm.Consider the Toeplitz operator Tzi : L2
a(Bm)→ L2a(Bm) by
Tzi(ξ) := ziξ.
Proposition
The commutators
[Tzi , T∗zj ], i, j = 1, ...,m,
are compact operators on L2a(Bm).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 37: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/37.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
Unit ball
Let Bm be the unit ball in the complex plane Cm.Let L2
a(Bm) be the Hilbert space of square integrable analyticfunctions on Bm with respect to the Lebesgue measure.Let z1, · · · , zm be the coordinate function on Cm.Consider the Toeplitz operator Tzi : L2
a(Bm)→ L2a(Bm) by
Tzi(ξ) := ziξ.
Proposition
The commutators
[Tzi , T∗zj ], i, j = 1, ...,m,
are compact operators on L2a(Bm).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 38: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/38.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
Toeplitz index theorem for Bm
Let T (Bn) be the unital C∗-algebra, norm closed ∗-subalgebraof B(L2
a(Bm)), generated by Tz1 , · · · , Tzm and K(L2a(Bm)).
Let C(S2m−1) be the algebra of continuous functions onS2m−1 = ∂Bm.We have the following short exact sequence of C∗-algebras,
0 −→ K(L2a(Bm)) −→ T (Bm) −→ C(S2m−1) −→ 0.
Theorem (Venugopalkrishna, Boutet de Monvel,Baum-Douglas-Taylor)
In K1(S2m−1), [T (D)] = [ /D], where /D is the Spinc Diracoperator associated to the CR structure on S2m−1.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 39: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/39.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
Toeplitz index theorem for Bm
Let T (Bn) be the unital C∗-algebra, norm closed ∗-subalgebraof B(L2
a(Bm)), generated by Tz1 , · · · , Tzm and K(L2a(Bm)).
Let C(S2m−1) be the algebra of continuous functions onS2m−1 = ∂Bm.We have the following short exact sequence of C∗-algebras,
0 −→ K(L2a(Bm)) −→ T (Bm) −→ C(S2m−1) −→ 0.
Theorem (Venugopalkrishna, Boutet de Monvel,Baum-Douglas-Taylor)
In K1(S2m−1), [T (D)] = [ /D], where /D is the Spinc Diracoperator associated to the CR structure on S2m−1.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 40: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/40.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
Toeplitz index theorem for Bm
Let T (Bn) be the unital C∗-algebra, norm closed ∗-subalgebraof B(L2
a(Bm)), generated by Tz1 , · · · , Tzm and K(L2a(Bm)).
Let C(S2m−1) be the algebra of continuous functions onS2m−1 = ∂Bm.
We have the following short exact sequence of C∗-algebras,
0 −→ K(L2a(Bm)) −→ T (Bm) −→ C(S2m−1) −→ 0.
Theorem (Venugopalkrishna, Boutet de Monvel,Baum-Douglas-Taylor)
In K1(S2m−1), [T (D)] = [ /D], where /D is the Spinc Diracoperator associated to the CR structure on S2m−1.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 41: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/41.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
Toeplitz index theorem for Bm
Let T (Bn) be the unital C∗-algebra, norm closed ∗-subalgebraof B(L2
a(Bm)), generated by Tz1 , · · · , Tzm and K(L2a(Bm)).
Let C(S2m−1) be the algebra of continuous functions onS2m−1 = ∂Bm.We have the following short exact sequence of C∗-algebras,
0 −→ K(L2a(Bm)) −→ T (Bm) −→ C(S2m−1) −→ 0.
Theorem (Venugopalkrishna, Boutet de Monvel,Baum-Douglas-Taylor)
In K1(S2m−1), [T (D)] = [ /D], where /D is the Spinc Diracoperator associated to the CR structure on S2m−1.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 42: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/42.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Toeplitz operators on the unit diskToeplitz operators on the ball
Toeplitz index theorem for Bm
Let T (Bn) be the unital C∗-algebra, norm closed ∗-subalgebraof B(L2
a(Bm)), generated by Tz1 , · · · , Tzm and K(L2a(Bm)).
Let C(S2m−1) be the algebra of continuous functions onS2m−1 = ∂Bm.We have the following short exact sequence of C∗-algebras,
0 −→ K(L2a(Bm)) −→ T (Bm) −→ C(S2m−1) −→ 0.
Theorem (Venugopalkrishna, Boutet de Monvel,Baum-Douglas-Taylor)
In K1(S2m−1), [T (D)] = [ /D], where /D is the Spinc Diracoperator associated to the CR structure on S2m−1.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 43: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/43.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Essential normalityGeometry and an index problem
Table of Contents
1 Toeplitz Index TheoremToeplitz operators on the unit diskToeplitz operators on the ball
2 Arveson-Douglas ConjectureEssential normalityGeometry and an index problem
3 Recent ProgressRadical caseNon-radical caseBeyond topology
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 44: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/44.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Essential normalityGeometry and an index problem
Arveson-Douglas Conjecture
Let A = C[z1, · · · , zm] be the algebra of polynomials ofm-variables.
Let I an ideal of A, and I be the closure of I in L2a(Bm).
Observation : I is an invariant subspace of L2a(Bm) with
respect to the operators Tz1 , · · · , Tzm .
Conjecture (Arveson-Douglas)
The commutators
[Tzi |I , (Tzj |I)∗], i, j = 1, ...,m,
are all compact.
Remark
When the above property holds, we say that I is essentiallynormal.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 45: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/45.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Essential normalityGeometry and an index problem
Arveson-Douglas Conjecture
Let A = C[z1, · · · , zm] be the algebra of polynomials ofm-variables.Let I an ideal of A, and I be the closure of I in L2
a(Bm).
Observation : I is an invariant subspace of L2a(Bm) with
respect to the operators Tz1 , · · · , Tzm .
Conjecture (Arveson-Douglas)
The commutators
[Tzi |I , (Tzj |I)∗], i, j = 1, ...,m,
are all compact.
Remark
When the above property holds, we say that I is essentiallynormal.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 46: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/46.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Essential normalityGeometry and an index problem
Arveson-Douglas Conjecture
Let A = C[z1, · · · , zm] be the algebra of polynomials ofm-variables.Let I an ideal of A, and I be the closure of I in L2
a(Bm).Observation : I is an invariant subspace of L2
a(Bm) withrespect to the operators Tz1 , · · · , Tzm .
Conjecture (Arveson-Douglas)
The commutators
[Tzi |I , (Tzj |I)∗], i, j = 1, ...,m,
are all compact.
Remark
When the above property holds, we say that I is essentiallynormal.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 47: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/47.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Essential normalityGeometry and an index problem
Arveson-Douglas Conjecture
Let A = C[z1, · · · , zm] be the algebra of polynomials ofm-variables.Let I an ideal of A, and I be the closure of I in L2
a(Bm).Observation : I is an invariant subspace of L2
a(Bm) withrespect to the operators Tz1 , · · · , Tzm .
Conjecture (Arveson-Douglas)
The commutators
[Tzi |I , (Tzj |I)∗], i, j = 1, ...,m,
are all compact.
Remark
When the above property holds, we say that I is essentiallynormal.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 48: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/48.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Essential normalityGeometry and an index problem
Arveson-Douglas Conjecture
Let A = C[z1, · · · , zm] be the algebra of polynomials ofm-variables.Let I an ideal of A, and I be the closure of I in L2
a(Bm).Observation : I is an invariant subspace of L2
a(Bm) withrespect to the operators Tz1 , · · · , Tzm .
Conjecture (Arveson-Douglas)
The commutators
[Tzi |I , (Tzj |I)∗], i, j = 1, ...,m,
are all compact.
Remark
When the above property holds, we say that I is essentiallynormal.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 49: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/49.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Essential normalityGeometry and an index problem
Arveson-Douglas Conjecture-Continued
Researchers from all over the world have studied this conjecture.And many cases of the Arveson-Douglas conjecture are verified.
The following are the techniques that have been applied.
1 Operator theory
2 Harmonic analysis
3 Geometry
4 Commutative algebra
5 PDE
6 Noncommutative geometry...
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 50: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/50.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Essential normalityGeometry and an index problem
Arveson-Douglas Conjecture-Continued
Researchers from all over the world have studied this conjecture.And many cases of the Arveson-Douglas conjecture are verified.The following are the techniques that have been applied.
1 Operator theory
2 Harmonic analysis
3 Geometry
4 Commutative algebra
5 PDE
6 Noncommutative geometry...
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 51: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/51.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Essential normalityGeometry and an index problem
Arveson-Douglas Conjecture-Continued
Researchers from all over the world have studied this conjecture.And many cases of the Arveson-Douglas conjecture are verified.The following are the techniques that have been applied.
1 Operator theory
2 Harmonic analysis
3 Geometry
4 Commutative algebra
5 PDE
6 Noncommutative geometry...
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 52: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/52.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Essential normalityGeometry and an index problem
Arveson-Douglas Conjecture-Continued
Researchers from all over the world have studied this conjecture.And many cases of the Arveson-Douglas conjecture are verified.The following are the techniques that have been applied.
1 Operator theory
2 Harmonic analysis
3 Geometry
4 Commutative algebra
5 PDE
6 Noncommutative geometry...
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 53: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/53.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Essential normalityGeometry and an index problem
Arveson-Douglas Conjecture-Continued
Researchers from all over the world have studied this conjecture.And many cases of the Arveson-Douglas conjecture are verified.The following are the techniques that have been applied.
1 Operator theory
2 Harmonic analysis
3 Geometry
4 Commutative algebra
5 PDE
6 Noncommutative geometry...
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 54: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/54.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Essential normalityGeometry and an index problem
Arveson-Douglas Conjecture-Continued
Researchers from all over the world have studied this conjecture.And many cases of the Arveson-Douglas conjecture are verified.The following are the techniques that have been applied.
1 Operator theory
2 Harmonic analysis
3 Geometry
4 Commutative algebra
5 PDE
6 Noncommutative geometry...
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 55: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/55.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Essential normalityGeometry and an index problem
Arveson-Douglas Conjecture-Continued
Researchers from all over the world have studied this conjecture.And many cases of the Arveson-Douglas conjecture are verified.The following are the techniques that have been applied.
1 Operator theory
2 Harmonic analysis
3 Geometry
4 Commutative algebra
5 PDE
6 Noncommutative geometry...
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 56: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/56.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Essential normalityGeometry and an index problem
Arveson-Douglas Conjecture-Continued
Researchers from all over the world have studied this conjecture.And many cases of the Arveson-Douglas conjecture are verified.The following are the techniques that have been applied.
1 Operator theory
2 Harmonic analysis
3 Geometry
4 Commutative algebra
5 PDE
6 Noncommutative geometry
...
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 57: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/57.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Essential normalityGeometry and an index problem
Arveson-Douglas Conjecture-Continued
Researchers from all over the world have studied this conjecture.And many cases of the Arveson-Douglas conjecture are verified.The following are the techniques that have been applied.
1 Operator theory
2 Harmonic analysis
3 Geometry
4 Commutative algebra
5 PDE
6 Noncommutative geometry...
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 58: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/58.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Essential normalityGeometry and an index problem
The quotient module
Let QI be the quotient L2a(Bm)/I. Then we have the following
exact sequence of Hilbert spaces.
0 −→ I −→ L2a(Bm) −→ QI −→ 0.
Proposition
The module I is essentially normal if and only if the quotientQI is essentially normal.
Let σe(QI) be the essential spectrum space associated to(Tz1 , · · · , Tzm), and T (QI) be the unital C∗-algebra generatedby Tz1 , · · · , Tzm and K(L2
a(QI)).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 59: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/59.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Essential normalityGeometry and an index problem
The quotient module
Let QI be the quotient L2a(Bm)/I. Then we have the following
exact sequence of Hilbert spaces.
0 −→ I −→ L2a(Bm) −→ QI −→ 0.
Proposition
The module I is essentially normal if and only if the quotientQI is essentially normal.
Let σe(QI) be the essential spectrum space associated to(Tz1 , · · · , Tzm), and T (QI) be the unital C∗-algebra generatedby Tz1 , · · · , Tzm and K(L2
a(QI)).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 60: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/60.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Essential normalityGeometry and an index problem
The quotient module
Let QI be the quotient L2a(Bm)/I. Then we have the following
exact sequence of Hilbert spaces.
0 −→ I −→ L2a(Bm) −→ QI −→ 0.
Proposition
The module I is essentially normal if and only if the quotientQI is essentially normal.
Let σe(QI) be the essential spectrum space associated to(Tz1 , · · · , Tzm), and T (QI) be the unital C∗-algebra generatedby Tz1 , · · · , Tzm and K(L2
a(QI)).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 61: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/61.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Essential normalityGeometry and an index problem
An index problem
We are interested in the following index problem.
Question (R. Douglas)
Suppose that the Arveson-Douglas conjecture holds true for anideal I. Identify the K-homology class [T (QI)] defined by thefollowing extension
0 −→ K(L2a(QI)) −→ T (QI) −→ C(σe(QI)) −→ 0,
in K1(σe(QI)).
Example
In the case that I = 0 and m = 1, the Toeplitz index theoremfor S1 = ∂D gives the answer to the above question.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 62: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/62.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Essential normalityGeometry and an index problem
An index problem
We are interested in the following index problem.
Question (R. Douglas)
Suppose that the Arveson-Douglas conjecture holds true for anideal I. Identify the K-homology class [T (QI)] defined by thefollowing extension
0 −→ K(L2a(QI)) −→ T (QI) −→ C(σe(QI)) −→ 0,
in K1(σe(QI)).
Example
In the case that I = 0 and m = 1, the Toeplitz index theoremfor S1 = ∂D gives the answer to the above question.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 63: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/63.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Essential normalityGeometry and an index problem
Geometry of the zero set
Let ZI be the zero set of the ideal I, i.e.
ZI := z|f(z) = 0, ∀f ∈ I.
Let ΩI be the intersection ΩI := ZI ∩ Bm with the boundary∂ΩI ⊂ S2m−1 = ∂Bm.
Intuition : The quotient space QI can be viewed as “L2a(ΩI)”.
Suppose that I is homogeneous, i.e. I is generated byhomogeneous polynomials.
f(λz1, · · · , λzm) ∈ I, ∀f ∈ I.
The zero variety ZI is equipped with a C∗-action, and ∂ΩI isequipped with an S1-action.Denote by YI := ∂ΩI/S
1, an algebraic subset of CPm−1.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 64: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/64.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Essential normalityGeometry and an index problem
Geometry of the zero set
Let ZI be the zero set of the ideal I, i.e.
ZI := z|f(z) = 0, ∀f ∈ I.
Let ΩI be the intersection ΩI := ZI ∩ Bm with the boundary∂ΩI ⊂ S2m−1 = ∂Bm.Intuition : The quotient space QI can be viewed as “L2
a(ΩI)”.
Suppose that I is homogeneous, i.e. I is generated byhomogeneous polynomials.
f(λz1, · · · , λzm) ∈ I, ∀f ∈ I.
The zero variety ZI is equipped with a C∗-action, and ∂ΩI isequipped with an S1-action.Denote by YI := ∂ΩI/S
1, an algebraic subset of CPm−1.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 65: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/65.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Essential normalityGeometry and an index problem
Geometry of the zero set
Let ZI be the zero set of the ideal I, i.e.
ZI := z|f(z) = 0, ∀f ∈ I.
Let ΩI be the intersection ΩI := ZI ∩ Bm with the boundary∂ΩI ⊂ S2m−1 = ∂Bm.Intuition : The quotient space QI can be viewed as “L2
a(ΩI)”.Suppose that I is homogeneous, i.e. I is generated byhomogeneous polynomials.
f(λz1, · · · , λzm) ∈ I, ∀f ∈ I.
The zero variety ZI is equipped with a C∗-action, and ∂ΩI isequipped with an S1-action.Denote by YI := ∂ΩI/S
1, an algebraic subset of CPm−1.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 66: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/66.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Essential normalityGeometry and an index problem
Geometry of the zero set
Let ZI be the zero set of the ideal I, i.e.
ZI := z|f(z) = 0, ∀f ∈ I.
Let ΩI be the intersection ΩI := ZI ∩ Bm with the boundary∂ΩI ⊂ S2m−1 = ∂Bm.Intuition : The quotient space QI can be viewed as “L2
a(ΩI)”.Suppose that I is homogeneous, i.e. I is generated byhomogeneous polynomials.
f(λz1, · · · , λzm) ∈ I, ∀f ∈ I.
The zero variety ZI is equipped with a C∗-action, and ∂ΩI isequipped with an S1-action.
Denote by YI := ∂ΩI/S1, an algebraic subset of CPm−1.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 67: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/67.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Essential normalityGeometry and an index problem
Geometry of the zero set
Let ZI be the zero set of the ideal I, i.e.
ZI := z|f(z) = 0, ∀f ∈ I.
Let ΩI be the intersection ΩI := ZI ∩ Bm with the boundary∂ΩI ⊂ S2m−1 = ∂Bm.Intuition : The quotient space QI can be viewed as “L2
a(ΩI)”.Suppose that I is homogeneous, i.e. I is generated byhomogeneous polynomials.
f(λz1, · · · , λzm) ∈ I, ∀f ∈ I.
The zero variety ZI is equipped with a C∗-action, and ∂ΩI isequipped with an S1-action.Denote by YI := ∂ΩI/S
1, an algebraic subset of CPm−1.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 68: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/68.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Essential normalityGeometry and an index problem
Grothendieck Riemann Roch Theorem
Theorem (Grothendieck)
Let i : YI → CPm−1 be the natural embedding. Assume that YIis smooth. The following commutative diagram holds.
K0(YI) K0(CPm−1)
A(YI) A(CPm−1)
-i!
?
Ch
?
Ch
-i∗
.
In particular, for E ∈ K0(YI),
i∗(Ch(E) ∪ Td(YI)) = Ch(i!(E)) ∪ Td(CPm−1).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 69: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/69.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Essential normalityGeometry and an index problem
Analytic Grothendieck Riemann Roch Theorem
When YI is not smooth, the geometric fundamental class of YIis not unique. Algebraic geometers have developed intersectionhomology, perverse sheaves, · · · , to study the generalization ofGrothendieck Riemann Roch Theorem.
Observation : Though the geometric fundamental class is notunique, the extension class [T (QI)]
S1 ∈ K0(YI) is canonicallydefined.
Conjecture (Douglas-T-Yu)
The extension class [T (QI)]S1
is a fundamental class of YI .
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 70: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/70.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Essential normalityGeometry and an index problem
Analytic Grothendieck Riemann Roch Theorem
When YI is not smooth, the geometric fundamental class of YIis not unique. Algebraic geometers have developed intersectionhomology, perverse sheaves, · · · , to study the generalization ofGrothendieck Riemann Roch Theorem.Observation : Though the geometric fundamental class is notunique, the extension class [T (QI)]
S1 ∈ K0(YI) is canonicallydefined.
Conjecture (Douglas-T-Yu)
The extension class [T (QI)]S1
is a fundamental class of YI .
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 71: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/71.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Essential normalityGeometry and an index problem
Analytic Grothendieck Riemann Roch Theorem
When YI is not smooth, the geometric fundamental class of YIis not unique. Algebraic geometers have developed intersectionhomology, perverse sheaves, · · · , to study the generalization ofGrothendieck Riemann Roch Theorem.Observation : Though the geometric fundamental class is notunique, the extension class [T (QI)]
S1 ∈ K0(YI) is canonicallydefined.
Conjecture (Douglas-T-Yu)
The extension class [T (QI)]S1
is a fundamental class of YI .
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 72: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/72.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
Table of Contents
1 Toeplitz Index TheoremToeplitz operators on the unit diskToeplitz operators on the ball
2 Arveson-Douglas ConjectureEssential normalityGeometry and an index problem
3 Recent ProgressRadical caseNon-radical caseBeyond topology
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 73: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/73.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
Result in the case of complete intersection I
Let I be generated by p1, · · · , pM ∈ A = C[z1, · · · , zm].
We make the following assumptions.
Assumption
1 M ≤ m− 2 ;
2 The Jacobian matrix (∂pi/∂zj)i,j is of maximal rank on theboundary ∂ΩI = ZI ∩ ∂Bm ;
3 ZI intersects ∂Bm transversely.
Theorem (Douglas-T-Yu)
Under the above assumptions, the ideal I and also the quotientQI are essentially normal.The K-homology class [T (QI)] is equal to [ /D], where /D is thespinc-Dirac operator defined by the CR-structure on ∂ΩI .
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 74: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/74.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
Result in the case of complete intersection I
Let I be generated by p1, · · · , pM ∈ A = C[z1, · · · , zm].We make the following assumptions.
Assumption
1 M ≤ m− 2 ;
2 The Jacobian matrix (∂pi/∂zj)i,j is of maximal rank on theboundary ∂ΩI = ZI ∩ ∂Bm ;
3 ZI intersects ∂Bm transversely.
Theorem (Douglas-T-Yu)
Under the above assumptions, the ideal I and also the quotientQI are essentially normal.The K-homology class [T (QI)] is equal to [ /D], where /D is thespinc-Dirac operator defined by the CR-structure on ∂ΩI .
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 75: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/75.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
Result in the case of complete intersection I
Let I be generated by p1, · · · , pM ∈ A = C[z1, · · · , zm].We make the following assumptions.
Assumption
1 M ≤ m− 2 ;
2 The Jacobian matrix (∂pi/∂zj)i,j is of maximal rank on theboundary ∂ΩI = ZI ∩ ∂Bm ;
3 ZI intersects ∂Bm transversely.
Theorem (Douglas-T-Yu)
Under the above assumptions, the ideal I and also the quotientQI are essentially normal.
The K-homology class [T (QI)] is equal to [ /D], where /D is thespinc-Dirac operator defined by the CR-structure on ∂ΩI .
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 76: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/76.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
Result in the case of complete intersection I
Let I be generated by p1, · · · , pM ∈ A = C[z1, · · · , zm].We make the following assumptions.
Assumption
1 M ≤ m− 2 ;
2 The Jacobian matrix (∂pi/∂zj)i,j is of maximal rank on theboundary ∂ΩI = ZI ∩ ∂Bm ;
3 ZI intersects ∂Bm transversely.
Theorem (Douglas-T-Yu)
Under the above assumptions, the ideal I and also the quotientQI are essentially normal.The K-homology class [T (QI)] is equal to [ /D], where /D is thespinc-Dirac operator defined by the CR-structure on ∂ΩI .
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 77: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/77.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
Some remarks
1 It was proved recently by Ronald Douglas and Yi Wangthat the first two assumptions that M ≤ m− 2 and theJacobian matrix (∂pi/∂zj)i,j is of maximal rank on theboundary ∂ΩI = ZI ∩ ∂Bm can be weakened and simplifiedto one assumption, namely“the zero variety ZI has isolated singularities away from∂(ΩI)”.
2 There is an independent work by Englis-Eschmeier, whichis called “Geometric Arveson-Douglas conjecture”.
3 Ideals satisfying the assumptions in the theorem areradical, i.e.f |ZI
= 0 if and only if f ∈ I.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 78: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/78.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
Some remarks
1 It was proved recently by Ronald Douglas and Yi Wangthat the first two assumptions that M ≤ m− 2 and theJacobian matrix (∂pi/∂zj)i,j is of maximal rank on theboundary ∂ΩI = ZI ∩ ∂Bm can be weakened and simplifiedto one assumption, namely
“the zero variety ZI has isolated singularities away from∂(ΩI)”.
2 There is an independent work by Englis-Eschmeier, whichis called “Geometric Arveson-Douglas conjecture”.
3 Ideals satisfying the assumptions in the theorem areradical, i.e.f |ZI
= 0 if and only if f ∈ I.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 79: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/79.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
Some remarks
1 It was proved recently by Ronald Douglas and Yi Wangthat the first two assumptions that M ≤ m− 2 and theJacobian matrix (∂pi/∂zj)i,j is of maximal rank on theboundary ∂ΩI = ZI ∩ ∂Bm can be weakened and simplifiedto one assumption, namely“the zero variety ZI has isolated singularities away from∂(ΩI)”.
2 There is an independent work by Englis-Eschmeier, whichis called “Geometric Arveson-Douglas conjecture”.
3 Ideals satisfying the assumptions in the theorem areradical, i.e.f |ZI
= 0 if and only if f ∈ I.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 80: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/80.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
Some remarks
1 It was proved recently by Ronald Douglas and Yi Wangthat the first two assumptions that M ≤ m− 2 and theJacobian matrix (∂pi/∂zj)i,j is of maximal rank on theboundary ∂ΩI = ZI ∩ ∂Bm can be weakened and simplifiedto one assumption, namely“the zero variety ZI has isolated singularities away from∂(ΩI)”.
2 There is an independent work by Englis-Eschmeier, whichis called “Geometric Arveson-Douglas conjecture”.
3 Ideals satisfying the assumptions in the theorem areradical, i.e.f |ZI
= 0 if and only if f ∈ I.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 81: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/81.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
Some remarks
1 It was proved recently by Ronald Douglas and Yi Wangthat the first two assumptions that M ≤ m− 2 and theJacobian matrix (∂pi/∂zj)i,j is of maximal rank on theboundary ∂ΩI = ZI ∩ ∂Bm can be weakened and simplifiedto one assumption, namely“the zero variety ZI has isolated singularities away from∂(ΩI)”.
2 There is an independent work by Englis-Eschmeier, whichis called “Geometric Arveson-Douglas conjecture”.
3 Ideals satisfying the assumptions in the theorem areradical, i.e.
f |ZI= 0 if and only if f ∈ I.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 82: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/82.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
Some remarks
1 It was proved recently by Ronald Douglas and Yi Wangthat the first two assumptions that M ≤ m− 2 and theJacobian matrix (∂pi/∂zj)i,j is of maximal rank on theboundary ∂ΩI = ZI ∩ ∂Bm can be weakened and simplifiedto one assumption, namely“the zero variety ZI has isolated singularities away from∂(ΩI)”.
2 There is an independent work by Englis-Eschmeier, whichis called “Geometric Arveson-Douglas conjecture”.
3 Ideals satisfying the assumptions in the theorem areradical, i.e.f |ZI
= 0 if and only if f ∈ I.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 83: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/83.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
An example of a non-radical ideal
When I is not radical, the geometry of the space ∂ΩI is notsufficient to catch the full information of the K-homology class[T (QI)]. This can be seen in the following example.
Example
For m = 2, consider the ideal I = 〈z21〉 / A = C[z1, z2].
The quotient QI can be written as the sum of two space
L2a,1(D)⊕ L2
a,2(D),
where D is the unit disk inside the complex plane C, andL2a,1(−) (and L2
a,2(−)) is the weighted Bergman space with
respect to the weight defined by the defining function 1− |z|2(and (1− |z|2)2).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 84: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/84.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
An example of a non-radical ideal
When I is not radical, the geometry of the space ∂ΩI is notsufficient to catch the full information of the K-homology class[T (QI)]. This can be seen in the following example.
Example
For m = 2, consider the ideal I = 〈z21〉 / A = C[z1, z2].
The quotient QI can be written as the sum of two space
L2a,1(D)⊕ L2
a,2(D),
where D is the unit disk inside the complex plane C, andL2a,1(−) (and L2
a,2(−)) is the weighted Bergman space with
respect to the weight defined by the defining function 1− |z|2(and (1− |z|2)2).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 85: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/85.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
An example of a non-radical ideal
When I is not radical, the geometry of the space ∂ΩI is notsufficient to catch the full information of the K-homology class[T (QI)]. This can be seen in the following example.
Example
For m = 2, consider the ideal I = 〈z21〉 / A = C[z1, z2].
The quotient QI can be written as the sum of two space
L2a,1(D)⊕ L2
a,2(D),
where D is the unit disk inside the complex plane C, andL2a,1(−) (and L2
a,2(−)) is the weighted Bergman space with
respect to the weight defined by the defining function 1− |z|2(and (1− |z|2)2).
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 86: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/86.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
A resolution type of result
We generalize the example of 〈z21〉 to the following result.
Theorem (Douglas-Jabbari-T-Yu)
Let I be an ideal of C[z1, · · · , zm] generated by monomials, andI be its closure in the Bergman space L2
a(Bm). There areBergman space like Hilbert A-modules A0 = L2
a(Bm),A1, · · · ,Aktogether with bounded A-module morphisms Ψi : Ai → Ai+1,i = 0, · · · , k − 1 such that the following exact sequence of Hilbertmodules holds
0 −→ I → L2a(Bm)
Ψ0−→ A1Ψ1−→ · · · Ψk−1−→ Ak −→ 0.
Like the example of 〈z21〉, the Hilbert A-module Ai, i = 1, · · · , k,
has a similar geometric structure as a direct sum of (weighted)Bergman spaces on lower dimensional balls.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 87: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/87.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
A resolution type of result
We generalize the example of 〈z21〉 to the following result.
Theorem (Douglas-Jabbari-T-Yu)
Let I be an ideal of C[z1, · · · , zm] generated by monomials, andI be its closure in the Bergman space L2
a(Bm). There areBergman space like Hilbert A-modules A0 = L2
a(Bm),A1, · · · ,Aktogether with bounded A-module morphisms Ψi : Ai → Ai+1,i = 0, · · · , k − 1 such that the following exact sequence of Hilbertmodules holds
0 −→ I → L2a(Bm)
Ψ0−→ A1Ψ1−→ · · · Ψk−1−→ Ak −→ 0.
Like the example of 〈z21〉, the Hilbert A-module Ai, i = 1, · · · , k,
has a similar geometric structure as a direct sum of (weighted)Bergman spaces on lower dimensional balls.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 88: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/88.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
K-homology class
As a corollary of the previous resolution type of result, weobtain the following identification of the K-homology class.
Theorem (Douglas-Jabbari-T-Yu)
Let T (Ai) be the unital C∗-algebra generated by Toeplitzoperators on Ai, and σei be the associated essential spectrumspace, i = 1, ..., k. In K1(σe1 ∪ · · · ∪ σek), the following equationholds,
[T (QI)] = [T (A1)]− [T (A2)] + · · ·+ (−1)k−1[T (Ak)],
Every algebra T (Ai), i = 1, · · · , k, can be identified as thealgebra of Toeplitz operators on square integrable holomorphicsections of a hermitian vector bundle on a disjoint union ofsubsets of Bm. In this way, we obtain a geometric identificationof the class [T (QI)].
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 89: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/89.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
K-homology class
As a corollary of the previous resolution type of result, weobtain the following identification of the K-homology class.
Theorem (Douglas-Jabbari-T-Yu)
Let T (Ai) be the unital C∗-algebra generated by Toeplitzoperators on Ai, and σei be the associated essential spectrumspace, i = 1, ..., k. In K1(σe1 ∪ · · · ∪ σek), the following equationholds,
[T (QI)] = [T (A1)]− [T (A2)] + · · ·+ (−1)k−1[T (Ak)],
Every algebra T (Ai), i = 1, · · · , k, can be identified as thealgebra of Toeplitz operators on square integrable holomorphicsections of a hermitian vector bundle on a disjoint union ofsubsets of Bm. In this way, we obtain a geometric identificationof the class [T (QI)].
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 90: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/90.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
K-homology class
As a corollary of the previous resolution type of result, weobtain the following identification of the K-homology class.
Theorem (Douglas-Jabbari-T-Yu)
Let T (Ai) be the unital C∗-algebra generated by Toeplitzoperators on Ai, and σei be the associated essential spectrumspace, i = 1, ..., k. In K1(σe1 ∪ · · · ∪ σek), the following equationholds,
[T (QI)] = [T (A1)]− [T (A2)] + · · ·+ (−1)k−1[T (Ak)],
Every algebra T (Ai), i = 1, · · · , k, can be identified as thealgebra of Toeplitz operators on square integrable holomorphicsections of a hermitian vector bundle on a disjoint union ofsubsets of Bm. In this way, we obtain a geometric identificationof the class [T (QI)].
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 91: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/91.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
Brieskorn varieties
Take m = 5. Consider the following polynomials
pk := (z1)2 + (z2)2 + (z3)2 + (z4)3 + (z5)6k−1, k ∈ N.
The origin 0 ∈ C5 is an isolated singularity of Zpk . Choose asufficiently small ε > 0. Let B5
ε be the ball of radius ε centeredat 0.The zero set Zpk intersects transversely with the sphereS9ε := ∂B5
ε .The intersection Zpk ∩ S9 is a topological 7-sphere, but has adistinct smooth structure with k = 1, ..., 28.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 92: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/92.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
Brieskorn varieties
Take m = 5. Consider the following polynomials
pk := (z1)2 + (z2)2 + (z3)2 + (z4)3 + (z5)6k−1, k ∈ N.
The origin 0 ∈ C5 is an isolated singularity of Zpk . Choose asufficiently small ε > 0. Let B5
ε be the ball of radius ε centeredat 0.
The zero set Zpk intersects transversely with the sphereS9ε := ∂B5
ε .The intersection Zpk ∩ S9 is a topological 7-sphere, but has adistinct smooth structure with k = 1, ..., 28.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 93: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/93.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
Brieskorn varieties
Take m = 5. Consider the following polynomials
pk := (z1)2 + (z2)2 + (z3)2 + (z4)3 + (z5)6k−1, k ∈ N.
The origin 0 ∈ C5 is an isolated singularity of Zpk . Choose asufficiently small ε > 0. Let B5
ε be the ball of radius ε centeredat 0.The zero set Zpk intersects transversely with the sphereS9ε := ∂B5
ε .
The intersection Zpk ∩ S9 is a topological 7-sphere, but has adistinct smooth structure with k = 1, ..., 28.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 94: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/94.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
Brieskorn varieties
Take m = 5. Consider the following polynomials
pk := (z1)2 + (z2)2 + (z3)2 + (z4)3 + (z5)6k−1, k ∈ N.
The origin 0 ∈ C5 is an isolated singularity of Zpk . Choose asufficiently small ε > 0. Let B5
ε be the ball of radius ε centeredat 0.The zero set Zpk intersects transversely with the sphereS9ε := ∂B5
ε .The intersection Zpk ∩ S9 is a topological 7-sphere, but has adistinct smooth structure with k = 1, ..., 28.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 95: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/95.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
New invariant is needed
Let Ik = 〈pk〉 be the principal ideal generated by pk. Ouranalytic Grothendieck Riemann Roch theorem applies to theideal Ik.
It states that the K-homology class [T (QIk)] associated to QIkis equal to the class [ /Dk], where /Dk is the spinc Dirac operatorassociated to the CR-structure on Zpk ∩ S9 = S7.Unfortunately, “K-homology invariant is not fine enough todetect smooth structures. ”
Question
Find the right analytic invariant to detect the smooth structureon Zpk ∩ S9.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 96: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/96.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
New invariant is needed
Let Ik = 〈pk〉 be the principal ideal generated by pk. Ouranalytic Grothendieck Riemann Roch theorem applies to theideal Ik.It states that the K-homology class [T (QIk)] associated to QIkis equal to the class [ /Dk], where /Dk is the spinc Dirac operatorassociated to the CR-structure on Zpk ∩ S9 = S7.
Unfortunately, “K-homology invariant is not fine enough todetect smooth structures. ”
Question
Find the right analytic invariant to detect the smooth structureon Zpk ∩ S9.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 97: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/97.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
New invariant is needed
Let Ik = 〈pk〉 be the principal ideal generated by pk. Ouranalytic Grothendieck Riemann Roch theorem applies to theideal Ik.It states that the K-homology class [T (QIk)] associated to QIkis equal to the class [ /Dk], where /Dk is the spinc Dirac operatorassociated to the CR-structure on Zpk ∩ S9 = S7.Unfortunately, “K-homology invariant is not fine enough todetect smooth structures. ”
Question
Find the right analytic invariant to detect the smooth structureon Zpk ∩ S9.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 98: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/98.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
New invariant is needed
Let Ik = 〈pk〉 be the principal ideal generated by pk. Ouranalytic Grothendieck Riemann Roch theorem applies to theideal Ik.It states that the K-homology class [T (QIk)] associated to QIkis equal to the class [ /Dk], where /Dk is the spinc Dirac operatorassociated to the CR-structure on Zpk ∩ S9 = S7.Unfortunately, “K-homology invariant is not fine enough todetect smooth structures. ”
Question
Find the right analytic invariant to detect the smooth structureon Zpk ∩ S9.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 99: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/99.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
A Hilbert bundle (work in progress)
Let u ∈ C− 0. Consider Ipk(u) = 〈pk − u〉, a family ofprinciple ideals.
Let Hku be the orthogonal complement of Ipk(u) in L2a(B5).
Proposition (Douglas-Jabbari-T-Yu)
The family Hku forms a Hilbert bundle Hk over the punctureddisk D∗ε0 with a sufficiently small radius ε0.And there is a canonical Hermitian connection ∇ on the Hilbertbundle Hku.
Remark
We would like to view (Hk,∇) as the analytic analog of theMilnor fibration in his study of hypersurfaces with isolatedsingularities.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 100: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/100.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
A Hilbert bundle (work in progress)
Let u ∈ C− 0. Consider Ipk(u) = 〈pk − u〉, a family ofprinciple ideals.Let Hku be the orthogonal complement of Ipk(u) in L2
a(B5).
Proposition (Douglas-Jabbari-T-Yu)
The family Hku forms a Hilbert bundle Hk over the punctureddisk D∗ε0 with a sufficiently small radius ε0.And there is a canonical Hermitian connection ∇ on the Hilbertbundle Hku.
Remark
We would like to view (Hk,∇) as the analytic analog of theMilnor fibration in his study of hypersurfaces with isolatedsingularities.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 101: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/101.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
A Hilbert bundle (work in progress)
Let u ∈ C− 0. Consider Ipk(u) = 〈pk − u〉, a family ofprinciple ideals.Let Hku be the orthogonal complement of Ipk(u) in L2
a(B5).
Proposition (Douglas-Jabbari-T-Yu)
The family Hku forms a Hilbert bundle Hk over the punctureddisk D∗ε0 with a sufficiently small radius ε0.
And there is a canonical Hermitian connection ∇ on the Hilbertbundle Hku.
Remark
We would like to view (Hk,∇) as the analytic analog of theMilnor fibration in his study of hypersurfaces with isolatedsingularities.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 102: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/102.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
A Hilbert bundle (work in progress)
Let u ∈ C− 0. Consider Ipk(u) = 〈pk − u〉, a family ofprinciple ideals.Let Hku be the orthogonal complement of Ipk(u) in L2
a(B5).
Proposition (Douglas-Jabbari-T-Yu)
The family Hku forms a Hilbert bundle Hk over the punctureddisk D∗ε0 with a sufficiently small radius ε0.And there is a canonical Hermitian connection ∇ on the Hilbertbundle Hku.
Remark
We would like to view (Hk,∇) as the analytic analog of theMilnor fibration in his study of hypersurfaces with isolatedsingularities.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 103: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/103.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
A Hilbert bundle (work in progress)
Let u ∈ C− 0. Consider Ipk(u) = 〈pk − u〉, a family ofprinciple ideals.Let Hku be the orthogonal complement of Ipk(u) in L2
a(B5).
Proposition (Douglas-Jabbari-T-Yu)
The family Hku forms a Hilbert bundle Hk over the punctureddisk D∗ε0 with a sufficiently small radius ε0.And there is a canonical Hermitian connection ∇ on the Hilbertbundle Hku.
Remark
We would like to view (Hk,∇) as the analytic analog of theMilnor fibration in his study of hypersurfaces with isolatedsingularities.
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem
![Page 104: An Analytic Grothendieck Riemann Roch Theorem - scu.edu.cn · Toeplitz operators on the unit disk Toeplitz operators on the ball Unit disk Let D be the unit disk in the complex plane](https://reader034.fdocuments.in/reader034/viewer/2022043010/5fa0326ef6ccfd3666278de7/html5/thumbnails/104.jpg)
Toeplitz Index TheoremArveson-Douglas Conjecture
Recent Progress
Radical caseNon-radical caseBeyond topology
Thank you !
Xiang Tang An Analytic Grothendieck Riemann Roch Theorem