Non-Tachyonic Type 0B Orientifolds, Non-Supersymmetric Gauge Theories and Cosmological RG Flow

TL;DR

The work constructs tachyon-free, non-supersymmetric gauge theories on D3 branes within Type 0B orientifolds (0') and studies their AdS/CFT duals. It shows that, at large $N$, these theories are conformal and equivalent to ${\cal N}=4$ SYM in the planar limit, while at finite $N$ a cosmological RG flow arises from dilaton tadpoles and a bulk cosmological constant, producing logarithmic running of the gauge coupling that aligns with gravity analysis up to two loops. The authors develop the low-energy actions, analyze stability in the bulk (no tachyon), and extend the construction to orbifold singularities to generate a class of non-conformal, large-$N$ theories with controlled 1/$N$ corrections and potential dualities. Overall, the paper provides a string-theoretic framework to realize and interrogate non-supersymmetric gauge theories via AdS/CFT, linking conformality, RG flow, and planar equivalence to well-understood supersymmetric parents.

Abstract

We discuss gauge theories on D3 branes embedded in special non-tachyonic orientifolds of the 0B string theory. In general, they correspond to non-supersymmetric SU(N) gauge theories with scalars in the adjoint representation and spinors in the (anti-)symmetric representation. We study these theories via the AdS/CFT correspondence and present evidence of their relation to N=4 SYM in the planar limit. We also discuss finite N properties, focusing in particular on the renormalization group flow. Up to two loops, the logarithmic running of the gauge coupling is described by the dilaton tadpole and the cosmological constant that naturally emerge on the string theory side.

Figures (2)

• Figure 1: Feynman rules for ${\cal N}=4\ $ SYM and for the non-supersymmetric theory. a) Fermion propagator and fermion-boson vertex. b) Feynman rules for the supersymmetric theory: both fermions and bosons are in the adjoint representation. c) In the non-supersymmetric orientifold theory bosons transform in the adjoint representation whereas fermions transform in the $\vcenter{}$ representation (and in the $\overline{\vcenter{}}$ rep.).
• Figure 2: a) The fermionic loop contribution to the vacuum polarization. b) A planar contribution in the supersymmetric theory. Fermions are in the adjoint representation. c) The arrows in the internal loop were reversed such that the fermions are now in the $\vcenter{}$ (and $\overline{\vcenter{}}$) representations.