On Continuum Effective Field Theories, Gravity and Holography

TL;DR

This paper investigates the limitations of continuum effective field theories coupled with gravity, demonstrating that holographic models can exhibit nonstandard gravitational effects and naturally incorporate dark matter.

Contribution

It shows that free continuum EFTs cannot couple consistently to standard gravity and provides holographic models that realize nonstandard gravity and dark matter phenomena.

Findings

Holographic continuum models deviate from standard gravity with an R^{-2} correction.

Holographic models can naturally include dark matter in brane-world scenarios.

Deviations between AdS and linear dilaton backgrounds affect gravitational behavior.

Abstract

We examine effective field theories (EFTs) with a continuum sector in the presence of gravity. We first explain, via arguments based on central charge and species scale, that an EFT with a free continuum cannot consistently couple to standard (i.e. 4D Einstein) gravity. It follows that EFTs with a free or nearly-free continuum must either have a finite number of degrees of freedom or nonstandard gravity. The latter claim is realized for holographically-defined continuum models. We demonstrate this by computing the deviations from standard gravity in a specific 5D scalar-gravity system that gives rise to a gapped continuum (i.e the linear dilaton background). We find an $R^{-2}$ deviation from the Newtonian potential. At finite temperature we find an energy density with matter-like behavior in the brane Friedmann equation, holographically induced from the bulk geometry. Thus, remarkably, a brane-world living in the linear dilaton background automatically contains dark matter. We also present a slightly more evolved asymptotically-AdS linear dilaton model, for which the deviations exhibit a transition between AdS and linear dilaton behaviors.