  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.

General Relativity and Quantum Cosmology;Cosmology and Nongalactic Astrophysics