Abstract :
We construct and analyze D-branes in superstring theories in even dimensions less than ten. The backgrounds under study are supersymmetric image where the level of the supercoset is tuned such as to provide bona fide string theory backgrounds. We provide exact boundary states for D-branes that are localized at the tip of the cigar image supercoset conformal field theory. We analyze the spectra of open strings on these D-branes and show explicitly that they are consistent with supersymmetry in image and 6. The low energy theory on the world-volume of the D-brane in each case is pure Yang–Mills theory with minimal supersymmetry. In the case with four macroscopic flat directions image, we realize an image super-Yang–Mills theory, and we interpret the backreaction for the dilaton as the running of the gauge coupling, and study the relation between R-symmetry breaking in the gauge theory and the backreaction on the RR axion.
