In ationTracesofQuantumGravityShortlyafterBigBangOriginofallstructureweseetoday CosmologicalIn ationNeededtosolveseveralproblemschiefamongthembeinghomogeneityandisotropyoftheUniverseonlargesca ID: 206456
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QuantumGravity In ation:TracesofQuantumGravity?(Shortlyafter)BigBang:Originofallstructureweseetoday! CosmologicalIn ation:Neededtosolveseveralproblems,chiefamongthembeinghomogeneityandisotropyoftheUniverseonlargescalesIn ationaryexpansion:drivenbythepotentialenergyofascalareld(in aton)Standarddescription:AweaklycoupledLagrangianforthein atonwithinQFTframework BUT:(afterPlancksatellitedata,March,2013)Thereareimportantconceptualproblemswiththatpicture:[A.Ijjasa,P.Steinhardt,A.Loeb,arXiv:1304.2785;arXiv:1402.6980]{initialconditionsproblem[1 2(r')2V(')]{\unlikeliness"problemMorerecently:BICEP2datamayindicate\large"gravitationalwaves(i.e.r0:2))in atonexcursionO(MP)ineldspace!beyondE ectiveFieldTheory? Gauge/GravityDualityNonperturbativemethodforstudyingstronglycoupledgaugetheoriesCanbuildIn ationarymodelswithinthegravitydualsofaclassofstronglycoupledgaugedtheoriesIsitpossibletondinthisclass:{modelswithlargein atonexcursion[O(MP)]?{solutiontounlikeliness(etc.)problem(s)? Gauge/GravityDuality(AdS/CFTcorrespondence) Twodi erentperspectivesonD-branesinstringtheory: gravitybackground[SUGRAsolution]openstringsBCsAstackoflargenumberofD-branes:Twosidesofdualityencodesamedegreesoffreedom[Thetwosideshaveequalpartitionfunctions!][gaugetheory] Lythbound:(forFTdescriptionofin ation)[D.Lyth,hep-th/9606387;S.Antusch,D.Nolde,arXiv:1404.1821]p rO(10�1)',where'-in atonexcursion)If'O(MP),thentensortoscalarratior0:1(Recall:BICEP2givesr&#x]TJ/; ;$.7;ࡱ ;&#xTf 4;.92; 0 ;&#xTd [;0:1,although?)LythboundforD-branein ation:[Baumann,McAllister,hep-th/0610285]In ation:probeD3-branemovinginanontrivialbackgroundsourcedbyNDp-branes,whereN&#x]TJ/; ;$.7;ࡱ ;&#xTf 4;.92; 0 ;&#xTd [;&#x]TJ/; ;$.7;ࡱ ;&#xTf 4;.92; 0 ;&#xTd [;1!'�4 N1=2MP)r0:1 WalkingIn ationarymodel:Twodynamicalscales!twoparametersc, Bound:'f(c; )MP!Inprinciple:Possibletondregion(s)ofparameterspace,where'islargeenoughtohaver&#x-277;0:1Inpractice:Workinprogress...[Diculty:Walkingsolutiononlyknownincertainlimit,whichisnotsuitable.Needtoexploreotherregionsofparameterspace.] Unlikelinessproblem:(Steinhardtetal.)Canbuildin ationarymodels(\slow-walking"in ation)withr1:D3probeinwalkingregionofknownlimitsolution[J.Erdmenger,S.Halter,C.Nunez,G.Tasinato,arXiv:1210.4179]Inthisclassofmodels:{Formofin atonpotential)no\unlikelinessproblem"{Initialconditionsproblemalsoautomaticallysolved[walkingregion!veryslowrollduetoavery atpotential)1 2(r')2V(')] SummaryNewobservationaldata:Restrictsetofviablein ationarymodelsLeadtoavarietyofproblems[unlikeliness,initialconditions,toosmallr]Newclassofmodelsfromwalkingbackgrounds:Couldavoidunlikeliness,initialconditionsproblemsCouldprovide'&MPandthusr�0:1Butstillworktodo... Thankyou!