[天体物理、宇宙学及物理学电子书合辑].cosmic.microwave.background.observables.ppt

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1、CosmicMicrowaveBackgroundCarloBaccigalupi,SISSACMBlecturesatTRR33,seethecompleteprogramatdarkuniverse.uni-hd.de/view/Main/WinterSchoolLecture5Theselecturesareavailableinpdfformatatpeople.sissa.it/~bacci/work/lecturesCMBobservablesOutlineGeneralitiesandhistoricalremark

2、sCosmologicalfossilsTotalintensityandpolarization:T,E,BAngularpowerspectraStatusoftheCMBobservationsSuggestedlecturesGeneralitiesandhistoricalremarksExpandinguniverse⇒CMBcompressionintheearlystagesofanexpandinguniversecauseslotsofradiationarisingfromthermonuclearexplo

3、sionsReactionsarerapidenoughtoachievethermalizationandablackbodyspectrumItispossibletocomputetherarefactioncausedbytheexpansionsincethatepochTherelicradiationispredictedtopeakinmicrowaves,temperatureofafewKelvin,knowntodayastheCosmicMicrowaveBackground(CMB,Gamowetal.1

4、948)GeorgeGamow,threeyearsoldinOdessa,Ukraine,1907DiscoveryCMB:whereandwhen?Opacity:λ=(neσT)-1«horizonDecoupling:λ≈horizonFreestreaming:λ»horizonCosmologicalexpansion,Thomsoncrosssectionandelectronabundanceconspiretoactivatedecouplingabout300000yearsaftertheBigBang,at

5、about3000KCMBphotontemperatureApostcardfromthebigbangFromtheStephanBoltzmannlaw,regionsathightemperatureshouldcarryhighdensityThelatterisactivatedbyperturbationswhichareintrinsicofthefluidaswellasofspacetimeThus,themapsoftheCMBtemperatureisakindofsnapshotofprimordialc

6、osmologicalperturbationsAnimationfromtheNASAWMAPteamCOsmicBackgroundExplorerFromCOBEtotheWilkinsonMicrowaveAnisotropyProbeAbout20yearsofinsightintooneofthemostimportantobservablesinphysicsLotsofexperiments,fromgroundaswellasthestratosphereAfantastictechnologicalanddat

7、aanalysisprogress,inparalleltotheorylambda.gfsc.nasa.govAnimationfromtheNASAWMAPteamCosmologicalfossilsCMBphysics:Boltzmannequationdphotons=metric+Comptonscatteringdtdbaryons+leptons=metric+ComptonscatteringdtCMBphysics:Boltzmannequationdneutrinos=metric+weakinteracti

8、ondtddarkmatter=metric+weakinteraction(?)dtmetric=photons+neutrinos+baryons+leptons+darkmatterCMBphysics:metricCMBPhysics:Co