11499

10562

كارشناسي ارشد

فيزيك

اصفهان: دانشگاه صنعتي اصفهان، دانشكده فيزيك

1395

ده، صدوسه ص.

فرهنگ لران

رضا خسروي

بهروز ميرزا، احمد شيرزاد

1395/07/14

فيزيك

ID10562

The Partition Function of a Closed String On S 1 S3 and S 1 D4 Orbifolds Farhad Razi f razi@ph iut ac ir 2016 Department of Physics Sciences Isfahan University of Technology Isfahan 84156 83111 Iran Supervisor F Loran loran@cc iut ac ir Advisor R Khosravi rezakhosravi@cc iut ac ir 2010 MSC 83E30 81T40 57R18 Keywords Conformal Field Theory Bosonic String Theory Partition Function Closed String Free Scalar Modular Invariance Compacti cation Winding Mode Orbifold AbstractIn this thesis we review conformal eld theory CFT which is a quantum eld theory with conformalsymmetries Then by studying the bosonic string theory we see that the bosonic string theory hasconformal symmetries therefore we are allowed to use algebra of CFT We see that the partitionfunction for a closed sting is equal to the free scalar partition function to the power of Twenty four The free scalar partition function is not modular invariant unless we compactify one of dimensionsof the space in this situation strings emerge which have winding modes Then we de ne orbifoldas a quotient space of a manifold and we investigate orbifold of a circular theory from geometricand Hilbert space view In the following we compute the closed string partition function on someorbifolds of S 1 circle First we review the computation of the S 1 Z2 orbifold partiton function then we compute the partition function for some non abelian orbifolds of the circular theory By computingthe S 1 D2 orbifold partition function we propound a supposal which is the determining of the S 1 Gorbifold partition function based on properties of the G group representation and the G subgroupsrepresentation and we see the soundness of our supposal by computing the S 1 S3 and S 1 D4 orbifoldspartition functions

فرهنگ لران

رضا خسروي

بهروز ميرزا، احمد شيرزاد