Long-Range Dark Matter Self Interaction - Berkeley Cosmology 长距离的暗物质的自相互作用的伯克利宇宙学

EvidenceforaLong-RangeDarkMatterSelfInteraction(“FifthForce”)GlennysR.FarrarCenterforCosmologyandParticlePhysicsNewYorkUniversitySeeGRF+RachelRosenastro-ph/0610298LongRangeInteractionof~GravitationalStrengthisGeneric!StringtheoryandmostextensionsoftheSMcontainfields,e.g.,moduli,whicharemasslessateveryorderofperturbationtheory=>verylongrange.~(MPl/vev)2andvev’sarenaturallyoforderMGUTorMPl=>gravitationalstrengthcoupling.MaybeYukawawithr5~m-1orr5~a(GF+Peeblesastro-ph/0307316)Mayhavemorecomplicateddependenceondistance,e.g.,Chameleonmodels.=>musttestforfifthforceonallscales.V(r)=VN(r)exp(-r/r5)IE0657-56“bulletcluster”Markevitchastro-ph/0511345Z=0.3Mach3.0±0.4vgas=4740±630km/s(actually,-550km/s)Tclus=14keV(Tifquiescent~10keV)IE0657-56in2004NEW--IE0657-56in2006Weak+StrongLensingSurfaceDensity(red)X-rayBrightness(white)FromBradacetalastro-ph/0608408DMproof:Cloweetal,astro-ph/0608Lensing=>Maincluster:M200=1.51015MsunV200=1740km/sSubcluster:M200=1.51014MsunFurthermore…Sub-clusterismovinginplaneofsky(<~8o).Sub-clusterisonitsfirstpass;wentalmostdirectlythroughcenterofmaincluster.GasbulletlagsDM.(model-independentdis-proofofMOND-instead-of-DM)DMsub-clustervelocity=4740+670-550km/sIfKeplerian,vplunging=21/2vcirc=3360km/sHowseriousisthis>2“discrepancy”?MorecarefulmodelingGRF+RachelRosen,astro-ph/0610298ConsidervariousdensityprofilesformainDMcluster.UseMassAccretionHistoryofWechsleretal(2002)UseactualMAHof12mostmassivesimulatedclustersFixinitialinfallvelocityto300km/s(600km/s)=>initialpositionandtimearenotindependent.Predictedfinalvelocityisinsensitivetostartingtime.“Fiducialmodel”predictsv=2950km/secObserved:v=4740km/s;v-1=4190km/s“Conspiracymodel”predictsv=3435km/secPredictionswithGravityAloneAtypicalMassAccretionHistory?ResultswithactualMassAccretionHistoryof12mostmassivehalosinM.WhitesimulationComparetoWechsleretalformula(redcurve)Mostextremecasehas10%biggervelocitythangivenbymeanMAHOtherUncertaintiesWeakLensing--Massalongline-of-sight:DecreasespredictedvelocityInterpretationofX-raydata--Trajectorynotexactlyinplaneofsky:IncreasesobservedvelocityDynamicalCalculation--Trajectorynotexactlythroughcenterofcluster:moredynamicalfriction=>DecreasespredictedvelocityUnseenMass--AddmaximumconsistentwithRosat:Increasespredictedvelocityby~10km/sHayashiandWhiteMNRAS370,L38(2006)andGRF+RARupdateHW:Parameterizedistributionofvsubcl/v200inMilleniumRun.HW:usingold(androunded)valuesofvsubclandv200find1/500chanceoffindingsubclusterasfastasbullet.FR:Sameanalysisbutupdatingvsubclandv200=>findprobability=0.810-7.FR:Withvsubcl=4190km/s,findprobability=10-3.SomeObservationalBenefitsofa5thForceLargescale,highprecisionsimulationsunderway(GRF,V.Springel)Helpsreconcile8fromWMAP(.75)andLargeScaleStructuresimulations(0.9-1.1)Helpsexplainfactor-10discrepancybetweenLCDMsimulationsandnumberofsuperclustersobservedinSDSS(Einastoetal,astro-ph/06…)HelpsexplaininsufficiencyofobservedDMsubstructuresingalaxiesReducesbaryonicfractioninclusters.Helpsemptyvoids;reduceslateaccretionGRF-Peeblesqualitativeargument:voidsemptier,lesslateaccretionConfirmedbyNusser,Gubser,Peeblessimulationastro-ph/0412586:staticcase,roughstatistics.SagittariusTidalStreams--evidencefororagainst5thforce?Law,Johnston,MajewskiApJ619:807,2005Law,Johnston,Majewski:Precessionoforbitalplane:OblateHaloL.o.s.velocities:ProlateHaloKesdenKamionkowski:Symmetrictails(?)constraintobesmallGRF:Prolate-oblatecontradictioncanbesolvedby>0--GF,KJ,PJEPinprogressMajewskietal.ApJ599:1082,2003(2MASSM-Stars,ages≤2GyrConclusionsInterpretingIE0657-56atfacevalueas“5th”force:r51Mpc~0.2-1Consistentwithpresentconstraints(Gradwohl&Frieman,ApJ398,1992)ImprovingIE0657-56measurements:Improvelensing,measureredshiftsofmorearcsModelgasdeceleration;reduceerrorongasbulletvelocityNeedlargestatisticsstudiesinothersystems(edgesofvoids,velocitydispersionvsweaklensing,…)SDSS….Smallerr5accessibleviaTidalTailsofdwarfgalaxiesinMilkyWay.Kesden&Kamionkowski2006IfDMexperiencesa5thforce,loopcorrections+EotWash=>DMwillbehard(impossible?)toseeindirectdetectionexpts