Cosmological and gravitational wave constraints on dark energy — Macarena Lagos (Universidad Andres Bello)

About 70% of the energy content of the Universe is dark energy, the component driving the accelerated expansion of the cosmos. For more than two decades the simplest model, a cosmological constant, has fit observations remarkably well. That picture is now being challenged. Combining maps of millions of galaxies from the DESI survey with supernova distances and the cosmic microwave background reveals a growing preference for dark energy that evolves in time. If it holds, it would point to new fundamental physics beyond our standard cosmological model. In this talk, I will discuss a candidate of evolving dark energy as a scalar field that couples directly to gravity, and fits current cosmological observations better than a cosmological constant. I will show how such a model can also be tested independently with gravitational waves (GWs). Because they propagate through the evolving Universe, GWs carry an imprint of evolving dark energy. I will discuss what the current LIGO-Virgo-KAGRA catalogue can already tell us, and how this dark energy could bias GW measurements of the expansion rate of the Universe.

Horarios: 6 Oct 2026

Publicado por: Gijs Mulders