Characteristic Scales of Baryon Acoustic Oscillations from Perturbation Theory: Nonlinearity and Redshift-Space Distortion Effects

摘要

Anacousticoscillationoftheprimevalphoton-baryonfluidaroundthedecouplingtimeimprintsacharacteristicscaleinthegalaxydistributiontoday,knownasthebaryonacousticoscillation(BAO)scale.Severalongoingand/orfuturegalaxysurveysaimtodetectandpreciselydeterminetheBAOscalesoastotracetheexpansionhistoryoftheuniverse.Weconsidernonlinearandredshift-spacedistortioneffectsontheshiftsoftheBAOscalein$$k$$-spaceusingperturbationtheory.TheresultingshiftsareindeedsensitivetodifferentchoicesforthedefinitionoftheBAOscale,whichneedstobekeptinmindinthedataanalysis.Wepresentatoymodeltoexplainthephysicalbehavioroftheshifts.WefindthattheBAOscaledefinedasinPercivaletal.(2007,ApJ,657,51)indeedshowsverysmallshifts($$lesssim$$1%)relativetothepredictioninlineartheoryinrealspace.Theshiftscanbepredictedaccuratelyforscaleswhereperturbationtheoryisreliable.