Ponente
Descripción
Tensions between independent cosmological probes continue to challenge the $\Lambda$CDM framework. The persistent ~5$\sigma$ discrepancy between early- and late-time determinations of the Hubble parameter remains unresolved, while recent DESI BAO measurements, when interpreted within $\Lambda$CDM, yield constraints on the sum of neutrino masses that increasingly conflict with lower bounds from particle physics. Dynamical dark energy models offer a possible route to relax the neutrino mass tension by introducing additional background-level degrees of freedom. In some cases, these models are even favored over a cosmological constant at more than ~4$\sigma$. However, such late-time extensions generally fail to resolve the Hubble tension and can, in fact, worsen it. Conversely, models that appear promising in raising $H_0$ tend to push the inferred neutrino mass bounds toward unrealistically small values, deepening the disagreement with oscillation experiments. This leaves us questioning whether a consistent resolution is still within reach, or whether we are instead confronted with an unavoidable trade-off. To address this, in this talk I will further explore the three-way interplay between dark sector physics, neutrino cosmology, and cosmic tensions, reviewing what a resolution could require in terms of new physics, and analyzing the role of potential unaccounted-for observational systematics in the data.
