CosmoFONDUE - Cosmological Fundamental Observables and Novel Discoveries in Universe Evolution

Session

Neutrino and astroparticle cosmology

2C

11 Jun 2025, 14:30

Main auditorium (École de physique, Quai Ernest-Ansermet 24, 1205 Genève, Suisse)

81. Introduction to particle cosmology

Julien Lesgourgues

11/06/2025, 14:30

Neutrino and astroparticle cosmology

talk

I will start with a brief review on current neutrino mass bounds, which are inevitably related to the current debate on tensions between observables and departures from the LambdaCDM model. I will mention additional properties of dark matter and dark radiation that will be exciting to test with forthcoming experiments. These models are difficult to integrate into a precise theoretical...

17. Impact of light sterile neutrinos on cosmic structure formation

Rui Hu (Chinese University of Hong Kong)

11/06/2025, 15:00

Neutrino and astroparticle cosmology

talk

Sterile neutrinos with masses on the $\mathrm{eV}$ scale are promising candidates to account for the origin of neutrino mass and the reactor neutrino anomalies. The mixing between sterile and active neutrinos in the early universe could result in a large abundance of relic sterile neutrinos, which depends on not only their physical mass $m_{\rm phy}$ but also their degree of thermalization,...

36. Hot axions and Neff: towards an understanding of hot QCD effects

Jacopo Ghiglieri (SUBATECH, Nantes)

11/06/2025, 15:20

Neutrino and astroparticle cosmology

talk

The axion can address the strong CP problem and also provide a promising dark matter candidate in the form of a condensate of zero-momentum modes. In addition, axion models feature an unavoidable “hot” ensemble of thermally-produced axions acting as dark radiation and thus subject to present and future constraints from the effective number of neutrinos $N_\mathrm{eff}$.
I will concentrate on...

14. Decaying Dark Matter from CMB to LSS

Mr Thomas Montandon (Laboratoire Univers et Particule de Montpellier (LUPM))

11/06/2025, 15:40

Neutrino and astroparticle cosmology

talk

The two-body Decaying Dark Matter (DDM) model extends the standard cold dark matter paradigm by allowing dark matter particles to decay into a massive daughter particle and a relativistic species. This scenario arises naturally in particle physics and has testable implications for cosmological observables. In this talk, I will introduce the model and present updated constraints on the dark...