Non-BPS D-branes and enhanced symmetry in an asymmetric orbifold

Michael Gutperle
2000 Journal of High Energy Physics  
In this paper properties of D branes in a nine dimensional asymmetric orbifold are discussed, using a (-1)^F_Lσ_1/2 projection, where F_L is the leftmoving space-time fermion number and σ_1/2 is a freely acting shift of order two. There are two types of non BPS D branes, which are stable at R>2 and R<2 respectively. At R=2 there is a perturbative enhancement of gauge symmetry and the two types of branes are related by a global bulk symmetry transformation. At this point in the moduli space the
more » ... ssociated boundary states are constructed using a free fermion representation of the theory. Some aspects of the enhancement of gauge symmetry in the S-dual type Ĩ theory are discussed.
doi:10.1088/1126-6708/2000/08/036 fatcat:dikcm3vqdbftdfjntq4vxsdz5y