Non-BPS branes in a type-l orbifold

Abstract

We analyse the spectrum of non-BPS branes in the type-1 theory on the orbifold 4/I 4. We present a detailed analysis of the action of the worldsheet parity Ω on the different D-brane boundary state sectors of type IIB on 4/I 4, using the covariant formulation. Using these results we derive the spectrum of branes in the type-I orbifold. We find ℤ 2- and ℤ- charged non-BPS branes. A study of the stability of these branes in the type-I orbifold is also presented. We find that the type-I non-BPS D-particle and D-instanton remain stable in the orbifold. The D-particle carries no charge whereas the non-BPS D-instanton can carry twisted R-R charge. Show more