G. Starkman - The Oddly Quiet Universe

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The SEENET-MTP Workshop JW2011 Scientific and Human Legacy of Julius Wess 27-28 August 2011, Donji Milanovac, Serbia

Transcript of G. Starkman - The Oddly Quiet Universe

  • 1. The Oddly QuietUniverse: How theCMB challengescosmologysstandard model Glenn D. StarkmanCraig Copi, Dragan Huterer & Dominik SchwarzFrancesc Ferrer, Amanda YohoNeil Cornish, David Spergel, & Eiichiro KomatsuPascal Vaudrevange,, Dan Cumberbatch; Jean-Philippe Uzan, Alain Riazuelo, Jeff Weeks,R. Trotta, Pascal Vaudrevange, Bob Nichols, Peter Freeman Joe Silk, Andrew Jaffe, Anastasia Anarchiou

2. COBE - DMR Click to edit Master text stylesSecond level Third level Fourth levelFifth level 3. The WMAP SkyNASA/WMAP Science team 4. COBE vs. WMAP 5. OutlineThe largest scaleproperties of the universe:Thethe angular problemlow-l / large-angle power l from Cl to C()spectrum ClBeyond Cl and C() seeing the solar system in the microwave backgroundAnd back:troubles in cosmological paradise 6. The WMAP SkyNASA/WMAP Science team 7. Angular Power Spectrum T = lmalm Ylm( , ) T = lmalm= (2l+1)-1 m |alm|2 Ylm( , ) Standardmodel for the origin of fluctuations (inflation): alm are independent Gaussian random6 parameter fit to ~38 points variables, with < alm alm> = Cl l l mm Sky is statistically isotropic and Gaussian randomALL interesting information in the sky is contained in ClCl = (2l+1)-1 m |alm| NASA/WMAP Science team 8. Measuring the shape of spaceClick to edit Master text styles Second level Third level Fourth level Fifth levelNASA/WMAP Science team 9. Click to edit Master text styles Cosmic Triangle Second level Third level Fourth level Fifth level 10. Angular Power Spectrum = 1 .0x 11. Is there anythinginteresting left to learn about the Universe onlarge scales? 12. Motivation: The Low-l Anomaly 13. Beyond Cl:Searches for Departures fromGaussianity/Statistical Isotropyangular momentum dispersion axes (da Oliveira-Costa, et al.)Genus curves (Park)Spherical Mexican-hat wavelets (Vielva et al.)Bispectrum (Souradeep et al.)North-South asymmetries in multipoint functions(Eriksen et al., Hansen et al.)Cold hot spots, hot cold spots (Larson and Wandelt)Land & Magueijo scalars/vectorsmultipole vectors (Copi, Huterer & GDS; Schwarz, SCH; CHSS; also Weeks; Seljak and Slosar; Dennis) 14. Multipole VectorsQ: What are the directions associated with the l th multipole:Tl (,) m almYlm (,) ?Dipole (l =1) :m a1mY1m (,) = (1) (x(1,1), y(1,1), z(1,1)) (sin cos , sin sin , cos )Advantages: 1) (1,1) is a vector, (1) is a scalar2) Only (1) depends on C1 15. Shape and Alignment of the Quadrupole and OctopoleA. de Oliveira-Costa, M. Tegmark, M. Zaldarriaga, A. Hamilton. Phys.Rev.D69:063516,2004astro-ph/0307282For each l, find the axis nl around which the angularmomentum dispersion :(L)2 m m2 |alm (nl)|2is maximizedResults: Probability octopole is unusually planar 1/20?? (dominated by |m| = 3 if z n3 ).n2 .n3=0.9838 1/60 16. Multipole Vectors General l, write:m almYlm (,) (l) [( (l,1))( (l, l) ) traces] - all{{alm, m=- l,, l}, l =(0,1,)2,} {(l) ,{ (l,i),l =1, l}, l = (0,1,)2,} Advantages: 1) (l,i) are vectors, (l) is a scalar2) Only (l) depends on C l 17. Maxwell Multipole Vectors m almYlm (,) = [ (u (l,1)) (u (l,l) )r -1]r=1 manifestly symmetric AND trace free: 2 (1/r) (r)J.C. Maxwell, A Treatise on Electricity and Magnetism, v.1, 1873 (1st ed.) 18. Notice: Area VectorsQuadrupole has 2 vectors, i.e. quadrupole is a planeOctopole has 3 vectors, i.e. octopole is 3 planesSuggests defining: w(l,i,j) ( (l,i) x (l,j)) area vectorsCarry some, but not all, of the informationFor the experts: w(2,2,2) || n2 octopole is perfectly planar if w(3,1,2) || w(3,2,3) || w(3,3,1)and then: n3 || w(3,I,j) 19. l=2&3 Area Vectorsl=3 normal l=3 normal equinoxl=2 normal l=2dipole normall=3 normal ticip eclP SGl=3 normal dipole equinox l=3 normal l=3 normal 20. Alignment probabilitiesProbability of the quadrupole and octopole planesbeing so aligned: (0.1-0.6)%Conditional probability of the aligned planes being soperpendicular to the plane of the solar system: (0.2-1.7)%Conditional probability of aligned planes perpendicularto the solar system pointing at the dipole/ecliptic: few% Net : < 10-5 21. Area vectors tell about the orientations ofthe normals of the multipole planesDONT include all the information(multipole vectors do)Can rotate the aligned planesabout their common axis! 22. l=2&3 : The Map 23. Quadrupole+OctopoleCorrelations -- Explanations:Cosmology?Cosmology -- youve got to be kidding? you choose: the dipole or the ecliptic ? 24. Quadrupole+Octopole Correlations -- Explanations: Systematics?CosmologySystematics -- but how do you get such an effect?esp., how do you get a N-S ecliptic asymmetry? (dipole mis-subtraction?)how do you avoid oscillations in the time-ordered data? 25. Angular Power SpectrumAt least 3 other majordeviations in the Cl in1st year data 26. Power spectrum: ecliptic plane vs. polesFirst Year WilkinsonMicrowave AnisotropyProbe (WMAP)Observations:The Angular PowerSpectrumG. Hinshaw, et.al., 2003,ApJS, 148, 135 --only v.1 on archive All 3 other major deviations are in the ecliptic polar Cl only!! 27. No Dip? Boomerang Collaboration 28. The case against a systematic (cont.) ArcheopsFerrer, Starkman & Yoho (in progress): the anomaly in the first peak is (largely orentirely) localized to a region around the north ecliptic pole representing < 10% ofthe sky. Statistical significance tbd. 29. Dip? What dip? 30. Different weighting schemes: in the CMB:dip to a small patch of the north ecliptic sky.Amanda Yoho, Francesc Ferrer, Glenn D.389 31. No first peak at the N pole? 32. No first peak at the N pole? 33. Quadrupole+Octopole Correlations -- Explanations: more galaxy?CosmologySystematicsThe Galaxy: has the wrong multipole structure (shape) is likely to lead to GALACTIC not ECLIPTIC/DIPOLE/EQUINOX correlations 34. Quadrupole+OctopoleCorrelations --Explanations: Foregrounds?SystematicsCosmologyThe GalaxyForegrounds -- difficult: 1. Changing a patch of the sky typically gives you: Yl0 2. Sky has 5x more octopole than quadrupole 3. How do you get a physical ring perpendicular to the ecliptic 4. Caution: can add essentially arbitrary dipole, which can entirely distortthe ring! (Silk & Inoue) 5. How do you hide the foreground from detection? TTCMB 35. Future data Dvorkin, Peiris & Hu: Planck TE cross-correlation will test models where asuperhorizon scale modulation of the gravitational potential field causes the CMBtemperature field to locally look statistically anisotropic, even though globally themodel preserves statistical homogeneity and isotropy.(x) = g1(x) [1 + h(x)] + g2(x)Where g1(x) and g2(x) are Gaussian random fields andh(x) is the modulating long-wavelength fieldFor dipolar h(x), predictions for the correlation between the first 10 multipoles of thetemperature and polarization fields can typically be tested at better than the 98% CL.For quadrupolar h, the polarization quadrupole and octopole should be moderatelyaligned. Predicted correlations between temperature and polarization multipolesout to = 5 provide testsat the 99% CL or stronger for quadrupolar models that makethe temperature alignment more than a few percent likely. 36. Future dataPlanck:different systematics (direct T measurement)Confirmation of low-l alignments significant 37. Future dataPlanck:different systematics (direct T measurement)Confirmation of low-l alignments significantTE correlations test particular models (Dvorkin, Peiris & Hu) of the quadrupole-octopole alignment 38. The Low-l AnomalyThe lowquadrupole 39. The Large-Angle Anomaly 40. The Angular CorrelationFunction, C( )C() = < T(1)T(2)>1.2=cos But (established lore):Click to edit Master text styles Second level C() = l Cl Pl(cos ()) Third level Fourth level Same information as Cl, just Fifth level differently organized IF C() is obtained by a full sky average or the sky is statistically isotropic, i.e. if =ll mmCl NASA/WMAP science team 41. Is the Large-Angle AnomalySignificant? One measure (WMAP1):S1/2 = -11/2 [C()]2 d cos Only 0.15% of realizations ofinflationary CDM universewith the best-fit parametershave lower S! 42. Is the Large-Angle Anomaly Significant?One measure (WMAP1):S1/2 = -11/2 [C()]2 d cos 43. The Low-l Anomaly?What Low-l Anomaly? 44. Two point angular correlationfunction -- WMAP1 45. Two point angular correlationfunction -- WMAP3 46. Statistics of C()S1/2 = -1 1/2 [C()]2 dcos 47. Origin of C() 48. Is it an accident?Only 2% of rotated and cut full skieshave this low a cut-sky S1/2 49. Statistics of C() 0.03% of realizations of the concordance modelof inflationary CDM have so little cut sky large-angle correlation ! Either: this reflects a .03% probable full skyC(), or a 5% probable C() and a 2%probably alignment with the galaxy 50. Statistics of C()Efstathiou, Ma and Hanson:Direct calculation of C() on the cut sky is asuboptimal estimator of C() on the full sky.The estimator which is optimal if the sky is GRSI(C() calculated from reconstructed full sky Cl) yieldsa larger S1/2, which is less significant in itssmallness. 51. Statistics of C()Response: So what ? This is completely consistent with what we said. What is odd is the CUT-SKY C() ! Not true anyway (CHSS in press): Reconstructed Cl are biased upward Weighted reconstructed Cl are not biased, but require smoothing when calculated at low Nside smoothing causes contamination When reconstructing full sky Cl from smoothed cut skies everything depends on how you fill the cut 52. Origin of C() 53. The Conspiracy theory: minimizing S1/2To obtain S1/2 < 971 with the WMAP Clrequires varying C2, C3, C4 & C5! 54. Reproducing C()To obtain S1/2>97%)and most of thost of those are much most fits with the theory than is the ofpoorer fundamental predictioninflationary data current cosmology!(Copi, GDS in preparation) 58. SUMMARY If you believe the observed full-sky CMB:There are signs that the sky is NOTstatistically isotropic These are VERY statistically significant(>>99.9%)