D-branes in non-critical superstrings and duality in N=1 gauge theories with flavor

TL;DR

This paper explores D-branes in a specific superstring background to understand flavor in N=1 gauge theories and provides a string-theoretic perspective on Seiberg duality.

Contribution

It introduces new D-branes in a non-critical superstring background and connects their boundary conformal field theories to electric-magnetic duality in N=1 SQCD.

Findings

Identification of new D-branes realizing flavor

Analysis of monodromies in boundary conformal field theories

String-theoretic understanding of Seiberg duality

Abstract

We study D-branes in the superstring background R^{3,1} \times SL(2,R)_{k=1}/U(1) which are extended in the cigar direction. Some of these branes are new. The branes realize flavor in the four dimensional N=1 gauge theories on the D-branes localized at the tip of the cigar. We study the analytic properties of the boundary conformal field theories on these branes with respect to their defining parameter and find non-trivial monodromies in this parameter. Through this approach, we gain a better understanding of the brane set-ups in ten dimensions involving wrapped NS5-branes. As one application, using the boundary conformal field theory description of the electric and magnetic D-branes, we can understand electric-magnetic (Seiberg) duality in N=1 SQCD microscopically in a string theoretic context.