PIRSA:20060051

Neutrinos in Cosmology after Planck: What are their masses, properties, and relationship with the Hubble tension?

APA

Escudero, M. (2020). Neutrinos in Cosmology after Planck: What are their masses, properties, and relationship with the Hubble tension?. Perimeter Institute for Theoretical Physics. https://pirsa.org/20060051

MLA

Escudero, Miguel. Neutrinos in Cosmology after Planck: What are their masses, properties, and relationship with the Hubble tension?. Perimeter Institute for Theoretical Physics, Jun. 23, 2020, https://pirsa.org/20060051

BibTex

          @misc{ scivideos_PIRSA:20060051,
            doi = {10.48660/20060051},
            url = {https://pirsa.org/20060051},
            author = {Escudero, Miguel},
            keywords = {Particle Physics},
            language = {en},
            title = {Neutrinos in Cosmology after Planck: What are their masses, properties, and relationship with the Hubble tension?},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2020},
            month = {jun},
            note = {PIRSA:20060051 see, \url{https://scivideos.org/index.php/pirsa/20060051}}
          }
          

Miguel Escudero Kings College Guildford

Talk numberPIRSA:20060051
Source RepositoryPIRSA
Collection

Abstract

Neutrinos are a key (although implicit) ingredient of the standard cosmological model, LambdaCDM. Firstly, neutrinos directly participate in neutron freeze out during BBN, and secondly, they represent 40% of the energy density of the Universe after electron positron annihilation up to almost matter radiation equality. The latter fact makes neutrinos a necessary element to understand CMB observations. 

In this talk, I will review the cosmological implications of neutrinos. I will explain how current cosmological observations can be used to constrain their masses, their abundances, and their properties -- such as their interaction rate with other species. In particular, I will highlight that the typically very stringent constraint on their masses can be substantially relaxed if neutrinos decay on cosmological timescales. I will illustrate the implications of neutrino decays in cosmology with a few well-motivated neutrino mass models in which neutrinos can decay. I will then show that Planck CMB observations are a powerful tool to constraint neutrino interactions with neutrinophilic bosons. In particular, I will demonstrate that Planck legacy constraints neutrinophilic bosons with couplings as small as 10^{-13} with neutrinos for boson masses in the 0.1 eV < m < 300 eV range. I will finish by reviewing the role neutrinos can play with regards to the outstanding Hubble tension. I will show that pseudogoldstone bosons (majorons) interacting with neutrinos right before recombination represent a well motivated possibility to ameliorate (and potentially solve) the Hubble tension.