# Dirichlet Branes on Orientifolds

Quiroz, N. & Stefanski, B. (2002). Dirichlet Branes on Orientifolds. Physical Review D (PRD), 66(026002), doi: 10.1103/PhysRevD.66.026002

 Preview
PDF

## Abstract

We consider the classification of BPS and non-BPS D-branes in orientifold models. In particular we construct all stable BPS and non-BPS D-branes in the Gimon-Polchinski (GP) and Dabholkar-Park-Blum-Zaffaroni (DPBZ) orientifolds and determine their stability regions in moduli space as well as decay products. We find several kinds of integrally and torsion charged non-BPS D-branes. Certain of these are found to have projective representations of the orientifold $\times$ GSO group on the Chan-Paton factors. It is found that the GP orientifold is not described by equivariant orthogonal K-theory as may have been at first expected. Instead a twisted version of this K-theory is expected to be relevant.

Item Type: Article Q Science > QC Physics School of Engineering & Mathematical Sciences > Department of Mathematical Science Author http://openaccess.city.ac.uk/id/eprint/1030