Nonlinear dynamics in the Einstein-Gauss-Bonnet gravity › is › shinkai › Viewgraphs ›...

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2 2017/10/12 @ Einstein Toolkit, Mallorca, Spain Nonlinear dynamics in the Einstein-Gauss-Bonnet gravity http://www.oit.ac.jp/is/~shinkai/ Hisaaki Shinkai (Osaka Inst. Tech., Japan) Who am I ? 1996-99 Postdoc at WashU. Newman-Penrose scalar in 3+1 language Cactus developer at the very initial phase Formulation Problem of Einstein equations Higher-dimensional numerical relativity Alternative Gravity Theories, Approaches Chair of the Board, KAGRA Scientific Congress

Transcript of Nonlinear dynamics in the Einstein-Gauss-Bonnet gravity › is › shinkai › Viewgraphs ›...

  • 22017/10/12 @ Einstein Toolkit, Mallorca, Spain

    Nonlinear dynamics in the Einstein-Gauss-Bonnet gravity

    http://www.oit.ac.jp/is/~shinkai/

    Hisaaki Shinkai (Osaka Inst. Tech., Japan)

    Who am I ?
1996-99 Postdoc at WashU. 
Newman-Penrose scalar in 3+1 language 
Cactus developer at the very initial phase
Formulation Problem of Einstein equations
Higher-dimensional numerical relativity
Alternative Gravity Theories, Approaches
Chair of the Board, KAGRA Scientific Congress

  • 32017/10/12 @ Einstein Toolkit, Mallorca, Spain

    Nonlinear dynamics in the Einstein-Gauss-Bonnet gravity

    http://www.oit.ac.jp/is/~shinkai/

    Hisaaki Shinkai (Osaka Inst. Tech., Japan)

    4-dim, 5-dim, 6-dim, 
… how dimensionality affects to dynamics? Gauss-Bonnet terms 
… how higher-order curvature terms affects to dynamics? 2 models
Colliding scalar pulses / Fate of wormholes Ref: HS & Torii , PRD 96(2017)044009 [arXiv:1706.02070]


  • Spheroidal matter collapse 4D vs 5D

  • 5D collapses -- proceed rapidly. -- towards spherically. -- AH forms in wider ranges.

    I = RabcdRabcd

    at I(tend)

    Spheroidal matter collapse 4D vs 5D

  • Dynamics in Gauss-Bonnet gravity?

    E>O PEB OFI HBOP HB>AFJD PB IO C I P FJD EBE>O PS O H PF J >J EBO 9 J J 9 E>O IFJFI I I>OO C OP>PF O EB F >H -3 O H PF J 


    FO BT B PBA P E>RB OFJD H> FP >R FA>J B CB>P B 
P E>O JBRB BBJ ABI JOP >PBA FJ C HH D >RFP

    JBS P F FJ J IB F >H BH>PFRFP 
A 7R RH B MTE 4 .+ (& ( & & + 


    4ISSI 4 ., (& ( & & 
6 9 EWTMI E 5 RHTMKWI (&- ,

    I E >PPBJPF JO FJ 3 II JFP 
8 EIHE R EYE 4 -. (&&. &( &&+ 


    E M 2 IMLEW : W &- (& (- & 
E M 2 IMLEW : W 4 .+ (& ( & &&- 


     Introduction

    B BRTMM 8 EIHE 4 - (&&+ ( &&(C 1L 2 7YEN 2 8 II C II 5WT L : 3-+ (& + )-(

  • Formulation for evolution [N+1]  Introduction (2)

    JFPF>H >H B . JOP PF J RF> . JC I>H > > E
2 EGN LR I M M ME HE E0 8 DR LM R 4 .) (& & & &

    BP C 0M >PF JO
TIEH FW GRPS MGE IH


  • Formulation for evolution [dual null]  Field Equations (1)

    x

    +x

    ⌃0

    Evolution

  • Formulation for evolution [dual null]  Field Equations (1)

  • matter variables  Field Equations (2)

  • evolution equations (1)  Field Equations (3)

  • evolution equations (2)  Field Equations (4)

  • @+ @�

    I(5) = RijklRijkl

    GR 5d: small amplitude waves  Colliding Scalar Waves

    flat background, normal scalar field

    x

    +x

    +x

    �x

  • @+ @�

    I(5) = RijklRijkl

    GR 5d: large amplitude waves  Colliding Scalar Waves

  • ��

    ����

    ��

    ����

    ��

    ����

    ��

    �� �� �� �� �� �� ��

    ������������������������������������������������������������

    GR 5d GaussBonnet 5d

    I(5) = RijklRijkl

    I(5) at origin

    x

    I(5) = RijklRijkl

    GaussBonnet 5d (negative α)

    ↵GB = +1

    ↵GB = �1

    ↵GB = 0

    ↵GB = �1

    ↵GB = +1

    ↵GB = 0

  •  Colliding Scalar Waves

    max (RijklRijkl

    )

    *4dim, 5dim, 6dim,… higher dim *Gauss-Bonnet coupling (α>0) ̶> less growth of curvature

    ↵GB = �1

    ↵GB = +1

    ↵GB = 0

    ��

    ����

    ��

    ����

    ��

    ����

    ��

    �� �� �� �� �� �� ��

    ������������������������������������������������������������

    I(5) at origin

    ↵GB = �1

    ↵GB = +1

    ↵GB = 0

    maximum of Kretschmann invariant

  • BH & WH are interconvertible?

    EB > B RB OFIFH> PE JP>FJ I> DFJ>HH P > BAO C> BO >JA >J B ABWJBA P > FJD E FV JO 3

    7JH PEB > O>H J>P B C PEB 3O AF B O SEBPEB 3OBR HRB FJ H O IFJ O ABJOFP SEF E FO DFRBJ H >HH

    , 3> S> A JP A 8E O / ) (

    Black Hole WormholeLocally defined

    by

    Achronal (spatial/null) outer TH ⇨ 1-way traversable

    Temporal (timelike) outer THs
⇨ 2-way traversable

    Einstein eqs.

    Positive energy density 
normal matter (or vacuum)

    Negative energy density 
“exotic” matter

    Appear-ance occur naturally

    Unlikely to occur naturally.
but constructible??

     Wormhole Evolution

  • BH & WH are interconvertible?

    EB > B RB OFIFH> PE JP>FJ I> DFJ>HH P > BAO C> BO >JA >J B ABWJBA P > FJD E FV JO 3

    7JH PEB > O>H J>P B C PEB 3O AF B O SEBPEB 3OBR HRB FJ H O IFJ O ABJOFP SEF E FO DFRBJ H >HH

    , 3> S> A JP A 8E O / ) (

    Black Hole WormholeLocally defined

    by

    Achronal (spatial/null) outer TH ⇨ 1-way traversable

    Temporal (timelike) outer THs
⇨ 2-way traversable

    Einstein eqs.

    Positive energy density 
normal matter (or vacuum)

    Negative energy density 
“exotic” matter

    Appear-ance occur naturally

    Unlikely to occur naturally.
but constructible??

     Wormhole Evolution

  • Wormhole evolution

    #+ = 0 #� = 0#+ = 0#� = 0

    x

    +x

    �x

    +x

    Positive Energy Input= add normal scalar field= subtract ghost field

    Negative Energy Input= add ghost scalar field

    Black Hole InflationaryExpansion

    4d GR ↵GB = 0 HS-Hayward PRD 66(2002) 044005

    ⌃(t)

    #+ = 0 #� = 0

    ⌃(t)

    #+ = 0#� = 0

    N RY JEG

  • �E > 0

    �E < 0

    4d GR ↵GB = 0 HS-Hayward PRD 66(2002) 044005

    #+ = 0 #� = 0#+ = 0#� = 0

    x

    +x

    �x

    +x

    Positive Energy Input= add normal scalar field= subtract ghost field

    Negative Energy Input= add ghost scalar field

    Black Hole InflationaryExpansion

    ⌃(t)

    #+ = 0 #� = 0

    ⌃(t)

    #+ = 0#� = 0

    Wormhole evolution N RY JEG

    真貝著 タイムマシンと時空の科学

  • 4-dim.

    5-dim.

    6-dim.

    x

    +x

    Sn�2

    #+ = 0#� = 0

    Positive Energy

    Black Hole

    In higher dim, large instability. (linear perturbation analysis)

    Wormhole evolution in n-dim n-dim GR Torii-HS PRD 88 (2013) 064027↵GB = 0

    N RY JEG

  • 4-dim.

    5-dim.

    6-dim.

    x

    +x

    Sn�2

    #+ = 0#� = 0

    Positive Energy

    Black Hole

    In higher dim, large instability. (linear perturbation analysis)

    Wormhole evolution in n-dim n-dim GR Torii-HS PRD 88 (2013) 064027↵GB = 0

    N RY JEG

    Confirmed Numerically

  • ↵GB = +0.001

    Wormhole evolution in Gauss-Bonnet のおさらい 5d Gauss-Bonnet WH : positive energy injection

    MSmass, H.Maeda-Nozawa, PRD77 (2008) 063031

    (a)

    0.0

    0.5

    1.0

    1.5

    2.0

    0.0 1.0 2.0 3.0 4.0 5.0 6.0

    Circumference radius of throat [5dim GB alpha=+0.001](with perturabation of positive-energy pulse)

    alpha=0.001, c1=0.1, E=+0.11alpha=0.001, c1=0.2, E=+0.46alpha=0.001, c1=0.3, E=+1.04alpha=0.001, c1=0.5, E=+2.85alpha=0.001, c1=0.7, E=+5.49

    circ

    umfe

    renc

    e ra

    dius

    of t

    he th

    roat

    proper time at the throat

    (a)

    ΔE > ΔE5 > 0 --> BH collapse ΔE < ΔE5 --> Inflationary expansion

    �E < +0.5

    �E > +0.5

  • ↵GB = +0.001

    Wormhole evolution in Gauss-Bonnet のおさらい 6d Gauss-Bonnet WH : positive energy injection

    MSmass, H.Maeda-Nozawa, PRD77 (2008) 063031

    ΔE > ΔE6 > ΔE5 > 0 --> BH collapse ΔE < ΔE5 < ΔE6 --> Inflationary expansion

    0.0

    0.5

    1.0

    1.5

    2.0

    0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

    Circumference radius of throat [6dim GB alpha=+0.001](with perturabation of positive-energy pulse)

    alpha=0.001, c1=0.50, E=+1.5276alpha=0.001, c1=0.60, E=+2.1954alpha=0.001, c1=0.65, E=+2.5790alpha=0.001, c1=0.70, E=+2.9896

    circ

    umfe

    renc

    e ra

    dius

    of t

    he th

    roat

    proper time at the throat

    (b)(b)

    �E > +2.2

    �E < +2.2

  • 0.0

    0.5

    1.0

    1.5

    2.0

    2.5

    3.0

    3.5

    4.0

    0.0

    0.5

    1.0

    1.5

    2.0

    2.5

    3.0

    3.5

    4.0

    horiz

    on lo

    catio

    ns

    (alph

    a=+0

    .01, w

    ith p

    ertur

    batio

    n of

    posit

    ive e

    nerg

    y)

    theta_

    +=0 :

    alph

    a=0.0

    1, a=

    0.0

    theta_

    -=0 : a

    lpha=

    0.01,

    a=0.0

    theta_

    +=0 :

    alph

    a=0.0

    1, a=

    0.5

    theta_

    -=0 : a

    lpha=

    0.01,

    a=0.5

    theta_

    +=0 :

    alph

    a=0.0

    1, a=

    0.6

    theta_

    -=0 : a

    lpha=

    0.01,

    a=0.6

    theta_

    +=0 :

    alph

    a=0.0

    1, a=

    0.7

    theta_

    -=0 : a

    lpha=

    0.01,

    a=0.7

    theta_

    +=0 :

    alph

    a=0.0

    1, a=

    0.8

    theta_

    -=0 : a

    lpha=

    0.01,

    a=0.8

    xminu

    sxp

    lus

    0.0

    0.5

    1.0

    1.5

    2.0

    2.5

    3.0

    3.5

    4.0

    0.0

    0.5

    1.0

    1.5

    2.0

    2.5

    3.0

    3.5

    4.0

    horiz

    on lo

    catio

    ns

    (alph

    a=+0

    .01, w

    ith p

    ertur

    batio

    n of

    posit

    ive e

    nerg

    y)

    theta_

    +=0 :

    alph

    a=0.0

    1, a=

    0.77

    theta_

    -=0 : a

    lpha=

    0.01,

    a=0.7

    7

    theta_

    +=0 :

    alph

    a=0.0

    1, a=

    0.78

    theta_

    -=0 : a

    lpha=

    0.01,

    a=0.7

    8

    theta_

    +=0 :

    alph

    a=0.0

    1, a=

    0.79

    theta_

    -=0 : a

    lpha=

    0.01,

    a=0.7

    9

    theta_

    +=0 :

    alph

    a=0.0

    1, a=

    0.80

    theta_

    -=0 : a

    lpha=

    0.01,

    a=0.8

    0

    xminu

    sxp

    lus

    critical behavior

    existence of trapped surface ̶> not necessary to form a BH

    ↵GB = 0.01

    5d Gauss-Bonnet WH : trapped surface

  •  Colliding Scalar Waves

    Summary

     Wormhole Evolution

    max (RijklRijkl

    )

    1 PE I ABHO PEB J I>H B PF JO - S G C>R FAFJD PEB > B> >J B C OFJD H> FP >HPE DE FP FO FJBRFP> HB

    CI JRW H LE M LI GTM MGE M WE MR JRTJRTPM K E 28 LI I M I GI RJ LI TESSIHTIKMR M LI 5M IM 72 KTE M HRI RHMTIG M HMGE I E JRTPE MR RJ E 28

    ΔE > ΔE6 > ΔE5 > 0 --> BH collapse ΔE < ΔE5 < ΔE6 --> Inflationary expansion