منابع مشابه
Orientifolds with discrete torsion
We show how discrete torsion can be implemented in D = 4, N = 1 type IIB orientifolds. Some consistency conditions are found from the closed string and open string spectrum and from tadpole cancellation. Only real values of the discrete torsion parameter are allowed, i.e. ǫ = ±1. Orientifold models are related to real projective representations. In a similar way as complex projective representa...
متن کاملDiscrete Torsion and Symmetric Products
In this note we point out that a symmetric product orbifold CFT can be twisted by a unique nontrivial two-cocycle of the permutation group. This discrete torsion changes the spins and statistics of corresponding secondquantized string theory making it essentially “supersymmetric.” The long strings of even length become fermionic (or ghosts), those of odd length bosonic. The partition function a...
متن کاملOn Orbifolds with Discrete Torsion
We consider the interpretation in classical geometry of conformal field theories constructed from orbifolds with discrete torsion. In examples we can analyze, these spacetimes contain " stringy regions " that from a classical point of view are singularities that are to be neither resolved nor blown up. Some of these models also give particularly simple and clear examples of mirror symmetry.
متن کاملRecent Developments in Discrete Torsion
In this short article we briefly review some recent developments in understanding discrete torsion. Specifically, we give a short overview of the highlights of a group of recent papers which give the basic understanding of discrete torsion. Briefly, those papers observe that discrete torsion can be completely understand simply as the choice of action of the orbifold group on the B field. We sum...
متن کاملThe Algebra of Discrete Torsion
We analyze the algebraic structures of G–Frobenius algebras which are the algebras associated to global group quotient objects. Here G is any finite group. These algebras turn out to be modules over the Drinfeld double of the group ring k[G]. We furthermore prove that discrete torsion is a universal group action of H(G, k∗) on G–Frobenius algebras by isomorphisms of the underlying linear struct...
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ژورنال
عنوان ژورنال: Physical Review D
سال: 2003
ISSN: 0556-2821,1089-4918
DOI: 10.1103/physrevd.68.126003