Tensions in cosmology: Hubble, S8 & neutrino masses

Speaker: Emmanuel Schaan

In this pedagogical review, I hope to provide a starting point for thinking about new-physics solutions to some of the ongoing tensions in cosmology, focusing on the Hubble parameter H0 and the amplitude of matter density fluctuations S8.I will present an intuitive but precise explanation of the methods used to measure H0, including the direct distance ladder, the CMB, and the inverse distance ladder approach. I will point out some of the challenges that new-physics solutions need to overcome.If time allows, I will also describe the S8 tension between early and late-Universe estimates of the matter fluctuations, and shed some light on the surprisingly tight cosmological upper bounds on neutrino masses.