[IP2I seminar] T. Chehab (OCA, Nice) - Review of Entangled Relativity : from compact objects to cosmology

jeudi 12 nov. 2026, 11:00 → 12:00 Europe/Paris

Dirac/RdC-Amphithéâtre (IP2I)

Entangled Relativity is a non-linear reformulation of General Relativity in which matter and spacetime are fundamentally inseparable. Despite its non-standard formulation, General Relativity is recovered as a limiting regime through an intrinsic decoupling mechanism originally identified in scalar-tensor theories.

In this talk, we review recent developments in Entangled Relativity, starting with its implications for high-density environments and then focusing on cosmology. A distinctive prediction of the theory is a variation of the Planck constant. As this variation is expected to be enhanced in high-density environments, we discuss its potential signatures in white dwarfs, neutron stars, and binary systems, and its possible constraints through electromagnetic and gravitational-wave observations. We also discuss its impact on thermal radiation, as a varying Planck constant is expected to leave imprints on the Cosmic Microwave Background.

We then turn to cosmology, where Entangled Relativity has non-trivial implications for dark matter, neutrino masses, and the variation of Newton’s constant even in early Universe. We review the cosmological dynamics of the theory and present recent constraints obtained through a Markov Chain Monte Carlo analysis using low-redshift data, including 33 measurements from cosmic chronometers and the Pantheon+SHOES compilation, which contains 1,701 Type Ia supernovae.

Together, these results illustrate how Entangled Relativity could be tested across astrophysical and cosmological scales.