天體物理宇宙學及物理學電子書合輯cosmicmicrowavebackgroundobservables課件

CosmicMicrowaveBackgroundCarloBaccigalupi,SISSACMBlecturesatTRR33,seethecompleteprogramatdarkuniverse.uni-hd.de/view/Main/WinterSchoolLecture5Theselecturesareavailableinpdfformatatpeople.sissa.it/~bacci/work/lecturesCMBobservablesOutlineGeneralitiesandhistoricalremarksCosmologicalfossilsTotalintensityandpolarization:T,E,BAngularpowerspectraStatusoftheCMBobservationsSuggestedlecturesExpandinguniverse?CMBcompressionintheearlystagesofanexpandinguniversecauseslotsofradiationarisingfromthermonuclearexplosionsReactionsarerapidenoughtoachievethermalizationandablackbodyspectrumItispossibletocomputetherarefactioncausedbytheexpansionsincethatepochTherelicradiationispredictedtopeakinmicrowaves,temperatureofafewKelvin,knowntodayastheCosmicMicrowaveBackground(CMB,Gamowetal.1948)GeorgeGamow,threeyearsoldinOdessa,Ukraine,1907DiscoveryCMB:whereandwhen?Opacity:λ=(neσT)-1?horizonDecoupling:λ≈horizonFreestreaming:λ?horizonCosmologicalexpansion,Thomsoncrosssectionandelectronabundanceconspiretoactivatedecouplingabout300000yearsaftertheBigBang,atabout3000KCMBphotontemperatureCOsmicBackgroundExplorerFromCOBEtotheWilkinsonMicrowaveAnisotropyProbeAbout20yearsofinsightintooneofthemostimportantobservablesinphysicsLotsofexperiments,fromgroundaswellasthestratosphereAfantastictechnologicalanddataanalysisprogress,AnimationfromtheNASAWMAPteamCosmologicalfossilsCMBphysics:Boltzmannequationdneutrinos

=metric+weakinteractiondtddarkmatter

=metric+weakinteraction(?)dtmetric=photons+neutrinos

+baryons+leptons+darkmatterCMBphysics:metricCMBPhysics:ComptonscatteringComptonscatteringisanisotropicAnanisotropicincidentintensitydeterminesalinearpolarizationintheoutgoingradiationAtdecouplingthathappensduetothefinitewidthoflastscatteringandthecosmologicallocalquadrupoleCMBanisotropy:polarization+++Gradient(E):Curl(B):CMBanisotropy:reionizatione-e-e-CMBanisotropy:lensingFormingstructures-lensesEBCMBanisotropy:lensingaccelerationLastscatteringAnisotropiesT(θ,φ),Q(θ,φ),U(θ,φ),V(θ,φ)X=T,E,BX(θ,φ)=ΣlmalmXYslm(θ,φ)sphericalharmonicss=0forT,2forQandUEandBmodeshaveoppositeparityAngularpowerspectrumT(θ,φ),Q(θ,φ),U(θ,φ),V(θ,φ)aXlm,X=T,E,BCl=Σm[(almX)(almY)*]/(2l+1)sphericalharmonicsinformationcompressionCMBangularpowerspectrumAngle≈200/ldegreesCMBangularpowerspectrumAngle≈200/ldegreesPrimordialpowerGravitywavesAcousticoscillationsReionizationLensingCMBangularpowerspectrumboomerangdasiWMAPCosmologicalconcordancemodelCosmologicalconcordancemodelCosmologicalconcordancemodelCMBanisotropystatistics:unknown,probablystillhiddenbysystematicsEvidenceforNorthsouthasymmetry(Hansenetal.2005)EvidenceforBianchimodels(Jaffeetal.2006)Poorconstraintsoninflation,theerrorisabout100timesthepredicteddeviationsfromGaussianity(Komatsuetal.2003)LensingdetectionoutofreachOthercosmologicalbackgrounds?Neutrinos:abundancecomparabletophotons,decouplingatMeV,coldasphotons,weakinteractionGravitywaves:decouplingatPlanckenergy,abundanceunknown,gravitationalinteractionMorale:insistwiththeCMB,stillformanyyears…that’sthebestwehaveforlong…SSuggestedreadingModernCosmologytextbookfromScottDodelsonMylecturenotesfromthecourseatSISSA,people.sissa.it/