Adding flavor to the gravity dual of non-commutative gauge theories

TL;DR

This paper investigates how adding flavor branes affects the spectrum and dynamics of mesons in non-commutative gauge theories using supergravity duals, revealing spectrum similarities at large non-commutativity and mode disappearance at intermediate values.

Contribution

It introduces a detailed analysis of flavor branes in non-commutative gauge theories, including meson spectra and string dynamics, extending previous models to include flavor effects.

Findings

Spectrum matches commutative theory at large non-commutativity

Some meson modes disappear at intermediate non-commutativity

Rotating strings exhibit tilted configurations but retain Regge and Coulomb behaviors

Abstract

We study the addition of flavor degrees of freedom to the supergravity dual of the non-commutative deformation of the maximally supersymmetric gauge theories. By considering D7 flavor branes in the probe approximation and studying their fluctuations we extract the spectrum of scalar and vector mesons as a function of the non-commutativity. We find that the spectrum for very large non-commutative parameter is equal to the one in the commutative theory, while for some intermediate values of the non-commutativity some of the modes disappear from the discrete spectrum. We also study the semiclassical dynamics of rotating open strings attached to the D7-brane, which correspond to mesons with large spin. Under the effect of the non-commutativity the open strings get tilted. However, at small(large) distances they display the same Regge-like (Coulombic) behaviour as in the commutative theory. We also consider the addition of D5-flavor branes to the non-commutative deformation of the N=1 supersymmetric Maldacena-Nunez background.