Distance-duality in theories with a nonminimal coupling to gravity

TL;DR

This paper demonstrates that nonminimal coupling in gravitational theories causes violations of the distance-duality relation, and uses observational data to constrain such models across a range of redshifts.

Contribution

It derives the impact of nonminimal coupling on distance-duality and provides observational constraints using supernovae and baryon acoustic oscillations.

Findings

Violation of Etherington's relation in NMC models

Constraints on power-law NMC models from supernovae data

Constraints on exponential NMC models from BAO measurements

Abstract

We show that gravitational theories with a nonminimal coupling (NMC) to the matter fields lead to a violation of Etherington's distance-duality relation, which relates the luminosity and angular diameter distances. We derive constraints on power-law and exponential NMC models using existing measurements of type Ia supernovae and baryon acoustic oscillations throughout the redshift range $0<z<1.5$. These complement previous constrains derived from cosmic-microwave background radiation and big-bang nucleosynthesis data.