HEP Colloquia 2023

by Dr Riccardo Murgia (GSSI)

Monday 19 Jun 2023, 14:30 → 16:30 Europe/Rome

Aula C (Department of Physics)

Probing Cosmology with gravitational waves, high energy satellites, and large-scale structure data

 

The $\Lambda$CDM model of cosmology has been incredibly successful in explaining most properties of a number of independent observations, such as the cosmic microwave background (CMB) anisotropy data from \emph{Planck}, and the formation and distribution of the large-scale structure (LSS) of the universe.
 

Nonetheless, the persistence of a number of cosmological tensions, besides the fact that the nature of DM and DE is still unveiled, has triggered huge theoretical efforts, aiming to develop alternative well-motivated scenarios capable to restore cosmological concordance, providing a better combined fit -- compared to $\Lambda$CDM -- to all present data.
To unambiguously verify/falsify signals of new physics beyond $\Lambda$CDM it is thus crucial to combine CMB and LSS data with complementary astrophysical observations probing different redshifts and scales. Any alternative theoretical framework must only introduce very limited phenomenological departures, in order to resolve the tensions without spoiling the tight limits from CMB and LSS. An efficient approach to test such departures is to develop flexible parameterizations to cover the phenomenology induced by broad classes of theoretical models, and then translate the constraints on the phenomenological parameter space into limits on the fundamental properties of the underlying theoretical scenarios.
In this talk, I will discuss how to exploit the synergy between widely used cosmological data and other complementary probes, such as structure formation data on non-linear scales, as well as gravitational wave and multi-messenger observations from next generation surveys. I will present up-to-date bounds and outline future perspectives regarding some of the most promising proposed alternative cosmological models.