Title: Neutrinos at the Intersection of Cosmological Tensions
The standard ΛCDM model has been remarkably successful in describing a wide range of cosmological observations. Nevertheless, as measurements become increasingly precise, several intriguing tensions have emerged. Neutrino oscillation experiments provide compelling evidence that neutrinos have mass, yet recent cosmological analyses within ΛCDM increasingly favor a total neutrino mass close to zero—and some phenomenological analyses even point toward formally “negative” neutrino masses. In this talk, I will review the impact of neutrino masses on cosmological observables and explore how shifts in cosmological parameters and their degeneracies connect neutrino-mass constraints to recent tensions between CMB and BAO measurements. I will discuss possible extensions beyond ΛCDM and other avenues for resolving or alleviating these tensions, including their connection to the Hubble tension. I will conclude by outlining how the next generation of cosmological observations could shed light on these tensions and further narrow the allowed range of neutrino properties, including their absolute mass scale and the effective number of relativistic species.
For Zoom information, please contact the seminar coordinators.
