K-Theory, Reality, and Orientifolds
نویسندگان
چکیده
We use equivariant K-theory to classify charges of new (possibly non-supersymmetric) states localized on various orientifolds in Type II string theory. We also comment on the stringy construction of new D-branes and demonstrate the discrete electric-magnetic duality in Type I brane systems with p+ q = 7, as proposed by Witten.
منابع مشابه
Orientifolds and K–theory
Recently it has been shown that D-branes in orientifolds are not always described by equivariant Real K–theory. In this paper we define a previously unstudied twisted version of equivariant Real K–theory which gives the Dbrane spectrum for such orientifolds. We find that equivariant Real K–theory can be twisted by elements of a generalised group cohomology. This cohomology classifies all orient...
متن کاملbranes , Orientifolds and K - theory
The complete D-brane spectrum in Z Z 2 orientifolds is computed. Stable non-BPS D-branes with both integral and torsion charges are found. The relation to K-theory is discussed and a new K-theory relevant to orientifolds is suggested.
متن کاملM theory on orientifolds of K3 x S1.
We present several Orientifolds of M-Theory on K 3 × S 1 by additional projections with respect to the finite abelian automorphism groups of K 3. The resulting models correspond to anomaly free theories in six dimensions. We construct explicit examples which can be interpreted as models with eight, four, two and one vector multiplets and N = 1 supersymmetry in six dimensions.
متن کاملNotes on discrete torsion in orientifolds
In this short note we discuss discrete torsion in orientifolds. In particular, we apply the physical understanding of discrete torsion worked out several years ago, as group actions on B fields, to the case of orientifolds, and recover some old results of Braun and Stefanski concerning group cohomology and twisted equivariant K theory. We also derive new results including phase factors for nono...
متن کاملF Theory Orientifolds, M Theory Orientifolds, and Twisted Strings
Orientifolds of the type IIB superstring that descend from F theory and M theory orbifolds are studied perturbatively. One finds strong evidence that a previously ignored twisted open string is required in these models. An attempt is made to interpret the J type torsion in F theory where one finds a realization of Gimon and Johnson’s models which does not require these twisted strings. S-dualit...
متن کامل