D-branes in non-critical superstrings and minimal super Yang-Mills in various dimensions

TL;DR

This paper constructs and analyzes D-branes in non-critical superstring backgrounds, revealing their world-volume theories as minimal supersymmetric Yang-Mills theories in various dimensions, and explores their gauge/gravity dualities.

Contribution

It provides exact boundary states for D-branes in non-critical superstring backgrounds and demonstrates their world-volume theories as minimal supersymmetric Yang-Mills theories in 2, 4, and 6 dimensions.

Findings

D-branes localized at the tip of the supercoset are constructed explicitly.

Open string spectra are consistent with supersymmetry in 2, 4, and 6 dimensions.

The low-energy world-volume theories are pure Yang-Mills with minimal supersymmetry.

Abstract

We construct and analyze D-branes in superstring theories in even dimensions less than ten. The backgrounds under study are supersymmetric R^{d-1,1} \times SL(2,R)_k / U(1) 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 SL(2,R)/U(1) 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 d=2,4 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 d=4, we realize an N=1 super Yang-Mills theory. 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.