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《RevModPhys.34.592The Conditions for a Quantum Field Theory to be Relativistic》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、REVIEWSOFMODERNPIYSICSVOLUME84,NUMBER4OCTOBER1962'..'.xeConcitions'..'.xeoryioraQuantum.«ie..cto~e.Xe..a1;ivisticP.A.M.DIBAGSt.John'sCollege,Cambridge,EnglandthiswayforoneparticularstateagainprovideaTHEBASICPROBLEMunitaryrepresentationoftheIHLG;infact,the~ONEcanbuild
2、upaquantumfieldtheorybysamerepresentationasbefore.ThissecondpictureW~workingfromaclassicalactionprinciple.IfoneistheoneneededforthedevelopmentofthetheorytakestheactiontobeLorentzinvariant,theclassicalthatwillbegivenhere.theorymustberelativistic.Withsuchanaction,byIfo
3、neworkedoutallunitaryrepresentationsoffollowingastandardmethod,onecanputtheclassi-theIHLG,onewouldobtainthetheoryofalldynam-calequationsofmotionintotheHamiltonianform.icalsystems,accordingtotheacceptedlawsofTheythenrefertotheconceptofastateatacertainquantummechanics.
4、time,whichisanonrelativisticconcept,sotheyareTheproblemofworkingoutallunitaryrepresenta-nolongermanifestlyrelativistic.Still,oneknowstionsoftheIHLGhasbeendealtwithbyWigner,'thattheymustberelativisticintheircontent,sincetakingthemathematicalpointofviewthattwotheyfollo
5、wentirelyfromLorentz-invariantassump-representationsareequivalentiftheyareconnectedtions.byaunitarytransformation.HedecomposestheWhenonepassesover—tothequantumtheoryonerepresentationsintotheirirreducibleconstituentsmakesnewassumptionsforexample,oneassumesandfindsthat
6、theirreducibleconstituentsprovideanorderfornoncommutingfactorsinaproduct-theoriesofelementaryparticleswithvariousspins.andtheconditionthattheoriginalactionshallbeThisworkdoesnotleadtoanyinteractionbetweenLorentzinvariantisnolongersufficienttoensureparticles.thattheth
7、eoryshallberelativistic.WemustmakeTobringininteraction,onemustdepartfromtheaspecialinvestigationtoseewhatisrequiredforapointofviewoflookingattworepresentationsasquantumfieldtheorytoberelativistic.equivalentiftheyareconnectedbyaunitarytrans-Atthebasisofquantummechanic
8、swehavetheformation,apointofviewwhichinvolveslookingprincipleofsuperpositionofstates.Wemustconsideruponallunitarytransformationsast
