Introduction to String Theory

《Introduction to String Theory》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。

1、IntroductiontoStringTheoryThomasMohauptFriedrich-SchillerUniversit¨atJena,Max-Wien-Platz1,D-07743Jena,GermanyAbstract.Wegiveapedagogicalintroductiontostringtheory,D-branesandp-branesolutions.1IntroductoryremarksThesenotesarebasedonlecturesgivenatthe271-thWE-Haereu

2、s-Seminar‘AspectsofQuantumGravity’.Theiraimistogiveanintroductiontostringtheoryforstudentsandinterestedresearches.Nopreviousknowledgeofstringtheoryisassumed.Thefocusisongravitationalaspectsandweexplaininsomedetailhowgravityisdescribedinstringtheoryintermsofthegrav

3、itonexcitationofthestringandthroughbackgroundgravitationalfields.WeincludeDirichletboundaryconditionsandD-branesfromthebeginninganddevoteonesectiontop-branesolutionsandtheirrelationtoD-branes.InthefinalsectionwebrieflyindicatehowstringtheoryfitsintothelargerpictureofM

4、-theoryandmentionsomeofthemorerecentdevelopments,likebraneworldscenarios.TheWE-Haereus-Seminar‘AspectsofQuantumGravity’coveredbothmainapproachestoquantumgravity:stringtheoryandcanonicalquantumgravity.Botharecomplementaryinmanyrespects.Whilethecanonicalapproachstre

5、ssesbackgroundindependenceandprovidesanon-perturbativeframework,thecor-nerstoneofstringtheorystillisperturbationtheoryinafixedbackgroundge-ometry.Anotherdifferenceisthatinthecanonicalapproachgravityandotherinteractionsareindependentfromeachother,whilestringtheoryaut

6、omaticallyisaunifiedtheoryofgravity,otherinteractionsandmatter.ThereisasingledimensionfulconstantandallcouplingsarefunctionsofthisconstantandofarXiv:hep-th/0207249v127Jul2002vacuumexpectationvaluesofscalars.Themattercontentisuniquelyfixedbythesymmetriesoftheunderlyi

7、ngstringtheory.Moreover,whenformulatingthetheoryinMinkowskispace,thenumberofspace-timedimensionsisfixed.Aswewillsee,thereareonlyfivedistinctsupersymmetricstringtheoriesinten-dimensionalMinkowskispace.ThemostimportantfeatureofstringperturbationtheoryistheabsenceofUVd

8、ivergencies.Thisallowsonetocomputequantumcorrectionstoscatter-ingamplitudesandtotheeffectiveaction,includinggravitationaleffects.Morerecently,significantpr