1、遼寧師范大學碩士學位論文關于五維時空中f（R)引力模型的研究姓名：李健申請學位級別：碩士專業(yè)：理論物理指導教師：吳亞波2012一i墾王!至笙墮窒叢旦里!壟夔型笪嬰窒———___———————————————————————’—————————————————一一highdimensionf(R)modalAbstractRecentobservationsoftypeIasupemovae(SNeIa)indicatethattheex

2、pansionoftheUniverseisacceleratingatpresenttimeButtheholbigbangmodelbasedontheordinarymattercomponentdenotesthattheexpansionofuniversewouldbedecelerating，whichisnotconsistentwiththeobservationInordertoexplaintheexpansion

3、ofourUniverse，wehavetomodifyitproperlyPeoplehaveproposedmanykindsoftheoriestoexplaintheacceleration，forexampledarkenergymodels，f(R)theoryandhigh—dimensionstheoryfromabovetheories，inthispaper，wediscussthetheoryofhigh—dime

4、nsionsf(R)theoryFirstofall，weintroducethebackgroundknowledgeofmodemcosmology，including；hierarchyproblem，finetuningproblem，thenweintroduceseveraldarkenergymodelsSecond，weintroducethebackgroundknowledgeofhigh—dimensiontheo

5、ry，therearethreefamoustheo—reticalmodels—ADD、RS、DGPmodelsFurthermore，weintroducethe：backgroundknowledgeofJ(R)theoryf(R)gravitywitharbitrarycouplingbetweenmatterandgeometryarederivedFinallythemetricf(R)theoriesofgravityar

6、egeneralizedtofive—dimensionalspacetimesByassumingahypersurface—orthogonalKillingvectorfieldrepresentingthecompactfifthdimension，thefive—dimensionaltheoriesarereducedtotheirfourdimensionalformalismThenwestudythecosmology

7、ofaspecialclassofmodelsinaspatiallyflatFRWspacetimeItisshownthattheparametersmandncanbeconstrainedtoacertainrangebythecurrentobsereeddecelerationparameter，andits；lowerboundcorrespondstotheKaluza—KleintheoryKeywords：high—