Résumé / Abstract Seminaire_IAP
« Cosmic relic neutrinos and large-scale structure: nonlinear clustering and the neutrino mass  »

Naoki Yoshida
Institute for the Physics and Mathematics of the Universe, Univ Tokyo (Tokyo, Japon)

A generic prediction of the standard Big Bang cosmology is the existence of a relic neutrino background that pervades the Universe. The dynamical influence of the permeating relic neutrinos is imprinted in the large-scale mass distribution in the Universe. We present the results from the state-of-the-art computer simulations of large-scale structure formation. The phase-space distribution of the cosmic relic neutrinos is followed, for the first time, by directly integrating the six-dimensional collisionless Boltzmann equation. Our novel approach allows us to reproduce free streaming and clustering of neutrinos, and their gravitational interaction with cold dark matter accurately. The effective local neutrino "temperature" around massive galaxy clusters varies by several percent with respect the cosmic mean; the neutrinos in clusters can be hotter or colder depending on the neutrino mass. Characteristic neutrino "wakes" are generated behind moving galaxies and galaxy clusters. Combining statistics of the neutrino distribution, we can derive tight constraints on the total mass of neutrinos from observations of large-scale structure. We discuss future prospects for obtaining further insight on the neutrino mass hierarchy.
vendredi 7 mai 2021 - 11:00
Webinaire, Institut d'Astrophysique de Paris
Page web du séminaire / Seminar's webpage