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1、February5,200816:50WSPC/INSTRUCTIONFILEFTestIntJMPDInternationalJournalofModernPhysicsDcWorldScienti?cPublishingCompanyANewTestforDarkEnergyModelsReuvenOpherInstitutodeAstronomia,Geof′?sicaeCi?enciasAtmosf′ericas,UniversidadedeS?aoPauloRuadoMat?ao1226,
2、CidadeUniversit′aria,CEP05508-900,S?aoPaulo,S.P.,Brazilopher@astro.iag.usp.brAnaPelinsonHighEnergyPhysicsGroup,Dept.ECM,UniversitatdeBarcelonaDiagonal647,E-08028,Barcelona,Catalonia,Spainapelinson@ecm.ub.esReceivedDayMonthYearRevisedDayMonthYearCommuni
3、catedbyManagingEditorOneofthegreatestchallengesincosmologytodayistodeterminethenatureofdarkenergy(DE),thesourceoftheobservedpresentaccelerationoftheUniverse.Besidesthevacuumenergy,variousDEmodelshavebeensuggested.Theteststhathavebeenproposedtodi?erenti
4、ateamongthesemodelsarebasedonobservationsofgalaxiesathighredshift(z>0),tobeobtainedinthefuture.Wesuggesthereanewtestthatisvalidatz?0.Itisbasedonexistingobservationaldata,numericalsimulations,andthreewellknownanalyticmodelsthatevaluatethebiasparameterb,
5、theratioofgalaxytodarkmatter(DM)?uctuations.TheseanalyticmodelsarebasedonthephysicalprocessesarXiv:astro-ph/0703779v25Jan2008involvedintheformationofstarsandintheformationandmergingofgalaxies.Thevalueofb(z)obtainedineachmodelisafunctionoftheDMgrowthfac
6、torD(z),which,inturn,isafunctionoftheDE.WeshowthattheequationsforbinallthreeanalyticmodelscanbereducedtotheformofaknownconstantplusthetermE[D(z=0)/D(z)]α,whereα=1or2andEisafreeparameter.Usingthevalueofbobtainedbythe2dFGRSconsortiumfortheΛCDMmodel,tonor
7、malizeE,we?ndthatallthreeanalyticmodelspredictb2(0)=1±0.1forallDEmodels.Sinceweusetheresultthatb2(0)?1fromthe2dFGRSconsortiumfortheΛCDMmodel,theL?galaxyusedinourtextisthesameasthatobtainedbytheconsortiumforabroadrangeofgalaxytypes,usingtheSchechterfunc
8、tion?ttotheoverallluminosityfunctionoftheir～220,000galaxies.Numericalsimulationsthatevaluatedb2(0)fortheΛCDMandCDM(Λ=0)modelsalsoobtainedb2(0)=1±0.1.Sincethisvalueofb2(0)isindicatedbynumericalsimulationsaswellasbyallthreepopularanalytic
