D-Branes and Dual Gauge Theories in Type 0 String Theory

TL;DR

This paper explores the construction of dual gauge theories in type 0 string theory by analyzing D-branes, addressing tachyon-induced instabilities, and proposing that R-R flux can stabilize the system and break conformal invariance.

Contribution

It demonstrates that R-R flux can stabilize the tachyon in type 0 string backgrounds, enabling the construction of duals for non-supersymmetric gauge theories.

Findings

R-R flux shifts the tachyon mass squared positively.

Tachyon acquires an expectation value in R-R flux background.

Potential to remove instabilities in non-supersymmetric duals.

Abstract

We consider the type 0 theories, obtained from the closed NSR string by a diagonal GSO projection which excludes space-time fermions, and study the D-branes into these theories. The low-energy dynamics of N coincident D-branes is governed by a U(N) gauge theory coupled to adjoint scalar fields. It is tempting to look for the type 0 string duals of such bosonic gauge theories in the background of the R-R charged p-brane classical solutions. This results in a picture analogous to the one recently proposed by Polyakov (hep-th/9809057). One of the serious problems that needs to be resolved is the closed string tachyon mode which couples to the D-branes and appears to cause an instability. We study the tachyon terms in the type 0 effective action and argue that the background R-R flux provides a positive shift of the (mass)^2 of the tachyon. Thus, for sufficiently large flux, the tachyonic instability may be cured, removing the most basic obstacle to constructing the type 0 duals of non-supersymmetric gauge theories. We further find that the tachyon acquires an expectation value in presence of the R-R flux. This effect is crucial for breaking the conformal invariance in the dual description of the 3+1 dimensional non-supersymmetric gauge theory.