# Effective interactions in Ricci-Based Gravity models below the non-metricity scale

## TL;DR

This paper investigates how matter fields interact within Ricci-Based Gravity models below a certain high-energy scale, deriving bounds on deviations from General Relativity, especially for Eddington-inspired Born-Infeld gravity.

## Contribution

It generalizes previous results to arbitrary matter fields and establishes bounds on the high-energy scale where Ricci-Based Gravity deviates from GR.

## Key findings

- Effective interactions develop below the scale Λ_Q
- Bounds on Λ_Q are derived for various Ricci-Based Gravity models
- Strong constraints are placed on Eddington-inspired Born-Infeld gravity

## Abstract

We show how minimally-coupled matter fields of arbitrary spin, when coupled to Ricci-Based Gravity theories, develop non-trivial effective interactions that can be treated perturbatively only below a characteristic high-energy scale $\Lambda_Q$. Our results generalize to arbitrary matter fields those recently obtained for spin 1/2 fields in \cite{Latorre:2017uve}. We then use this interactions to set bounds on the high-energy scale $\Lambda_Q$ that controls departures of Ricci-Based Gravity theories from General Relativity. Particularly, for Eddington-inspired Born-Infeld gravity we obtain the strong bound $ |\kappa|<3.5 \times 10^{-14} \text{ m}^5 \text{kg}^{-1}\text{s}^{-2} $.