6370

402 دكتري

دكتري

فيزيك

اصفهان: دانشگاه صنعتي اصفهان، دانشكده فيزيك

1389

[هشت]،90ص.: مصور

ص.ع.به فارسي و انگليسي

احمد شيرزاد

كيوان آقابابايي ساماني

29/8/90

فرهاد اردلان، فردين خير انديش

فيزيك

ID402 دكتري

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

The reduced phase space of an open string in the presence of background B field Mehdi Dehghani mdehghani@ph iut ac ir October 17 2010 Department of Physics Isfahan University of Technology Isfahan 84156 83111 IranAhmad Shirzad supervisor shirzad@ipm irKeivan Aghababaei Samani advisor samani@cc iut ac irF ShahbaziAbstractIn this thesis we investigate the problem of boundary condition as Dirac constraints We do thisby considering two theories with special boundary condition We find that boundary conditionsconfirm definition of constraints in the constrained system Then we show such constraints are ofsecond class one generally and are useful for constructing reduced phase space In both twosystems that we investigate we show the number of constraints is infinitely countable Anotherproblem is realization of above mentioned constraints for reducing non physical degrees offreedom We do this by assuming suitable Fourier expansions One of the considered systems inthis research is abstract WN model Firstly we analysis this model in a first class scheme and findits gauge fixing conditions in a systematic way Then we investigate its boundary conditions asDirac constraints By its constraints we find corresponding reduced phase space First classanalysis and seek for gauge fixing is a type of reduced phase space construction for ab initioabstract model Key Words Mixed boundary condition Second class constraint reduced phase space Dirac bracket Department of Physics Isfahan University of Technology Isfahan 84156 83111 Iran

احمد شيرزاد

كيوان آقابابايي ساماني