Fifth-Force Constraints from UV-Complete Scalar-Tensor Gravity

TL;DR

This paper investigates UV-complete scalar-tensor gravity models, deriving constraints on fifth-force parameters, and shows that upcoming experiments can test and potentially falsify these theories.

Contribution

It provides a novel analysis of UV completeness constraints on scalar-tensor theories and links theoretical bounds to experimental fifth-force searches.

Findings

UV completeness restricts the allowed parameter space in the (lpha,mbda) plane.

Part of the excluded parameter space is below current experimental bounds.

Future fifth-force experiments can test and potentially falsify these UV-complete models.

Abstract

We study an $O(N)$ scalar multiplet nonminimally coupled to gravity and follow its renormalization-group (RG) flow in the vicinity of an interacting, nonperturbatively UV-complete scaling regime of scalar-tensor theory. In the broken phase, the radial mode mediates a universal Yukawa correction to Newtonian gravity, parametrized by a strength $\alpha$ and range $\lambda$. Imposing UV completeness -- regular RG trajectories that reach the UV scaling regime -- restricts the infrared data to a finite wedge, which maps to a narrow region in the $(\alpha,\lambda)$ plane. Its complement is, therefore, ruled out by UV completeness alone. Remarkably, part of this theory-excluded domain lies below current experimental exclusion envelopes, so improved fifth-force searches can directly test and potentially falsify this class of UV-complete scalar-tensor models.