Causality Constraint on Noncritical Einstein-Weyl Gravity

TL;DR

This paper investigates causality constraints in five-dimensional Noncritical Einstein-Weyl gravity within the AdS/CFT framework, deriving a new bound on Weyl-squared coupling that enhances the theory's predictive accuracy.

Contribution

It introduces a causality-based bound on Weyl-squared coupling in NEW gravity, surpassing previous tachyon-free conditions, thus refining the theory's constraints.

Findings

Causality constraints impose a new bound on Weyl-squared coupling.

The new bound is more restrictive than the tachyon-free condition.

Enhanced predictive power of the NEW gravity model.

Abstract

We explore, in the context of AdS/CFT correspondence, the causality constraints on the Noncritical Einstein-Weyl (NEW) gravity model in five dimensions. The scalar and shear channels are considered as small metric perturbations around an AdS black brane background. Our results show that causality analysis on the propagation of these two channels imposes a new bound on the coupling of the Weyl-squared terms in the NEW gravity. This new bound imposes more stringent restrictions than those of the tachyon-free condition, improving predictive power of the theory.