Generalized Quantum Theory of Recollapsing Homogeneous Cosmo
时间:2025-07-11
时间:2025-07-11
A sum-over-histories generalized quantum theory is developed for homogeneous minisuperspace type A Bianchi cosmological models, focussing on the particular example of the classically recollapsing Bianchi IX universe. The decoherence functional for such uni
4
2
r
Ap
4
3
v
71
1
9
3
/
c
q
-
r
:gv
i
X
r
agr-qc/0309117GeneralizedQuantumTheoryofRecollapsingHomogeneousCosmologiesDavidCraig DepartmentofPhysics,HamiltonCollege,Clinton,NY13323JamesB.Hartle DepartmentofPhysics,UniversityofCaliforniaSantaBarbara,CA93106-9530(Dated:February7,2008)AbstractAsum-over-historiesgeneralizedquantumtheoryisdevelopedforhomogeneousminisuperspacetypeABianchicosmologicalmodels,focussingontheparticularexampleoftheclassicallyrecol-lapsingBianchiIXuniverse.Thedecoherencefunctionalforsuchuniversesisexhibited.Weshowhowtheprobabilitiesofdecoherentsetsofalternative,coarse-grainedhistoriesofthesemodeluni-versescanbecalculated.Weconsiderinparticulartheprobabilitiesforclassicalevolutionde nedbyasuitablecoarse-graining.Forarestrictedclassofinitialconditionsandcoarsegrainingsweexhibittheapproximatedecoherenceofalternativehistoriesinwhichtheuniversebehavesclas-sicallyandthoseinwhichitdoesnot.Forthesesituationsweshowthattheprobabilityisnearunityfortheuniversetorecontractclassicallyifitexpandsclassically.Wealsodeterminetherelativeprobabilitiesofquasi-classicaltrajectoriesforinitialstatesofWKBform,recoveringforsuchstatesapreciseformofthefamiliarheuristic“J·dΣ”ruleofquantumcosmology,aswellasageneralizationofthisruletogenericinitialstates.PACSnumbers:03.65.Ca,03.65.Yz,04.60.Gw,04.60.Kz,04.60.-m,98.80.Qc
下一篇:09年度工作总结