If the dark matter in the Universe is made of $\mu$eV axion-like particles (ALPs), then a rich phenomenology can emerge in connection to their stimulated decay into two photons. We discuss the ALP stimulated decay induced by astrophysical beams of Galactic radio sources. Three signatures, made by two echoes and one collinear emission, are associated with the decay, and can be simultaneously...
In this talk I will discuss how Supernovae (SN) can be exploited to severely constrain the parameter space of axion-like-particles (ALPs) coupled to nucleons. In particular, I will provide a continuous extension of the ALP emission rates to the case of strong nuclear couplings, in which they could enter the trapping regime. This approach allowed us to extend the usual cooling bound on...
This presentation delves into recent developments in string cosmology, specifically focusing on the refinement of the Hohm-Zwiebach approach through an Hamiltonian reformulation. A general criterion is established to have $O(d,d)$ invariant actions to all orders in $\alpha'$ connecting $T$-duality related perturbative solutions of string cosmology equations. Assuming a timely approach to the...
I will present a new framework for baryogenesis and leptogenesis based on a supercooled confining first order phase transition (PT).
With respect to the case of weakly coupled PTs, the rate asymmetry is enhanced by the decays of hadrons of the strong dynamics after the PT and washout effects from inverse decays are suppressed.
Therefore, our setup extends the parameter space of successful...
We discuss the phenomenology of neutrino decoupling in the early universe, by summarising the details of the calculation in standard and non-standard scenarios. We quickly present the state-of-the-art calculation of the effective number of neutrino species in the early universe (Neff) in the three-neutrino case, which gives Neff=3.044, and show how the result can change when additional...
In this talk, we present different inflationary scenarios based on extended theories of gravity and test their observational viability in light of the most recent CMB data. In the first part, we will analyze the robustness of the standard Starobinsky inflation by inserting it into a generalized framework that is motivated in the braneworld scenario. Following this line, we consider the period...
When Sub-GeV dark matter (DM) scatters off nuclei it makes them recoil too faintly to be seen by leading detectors. The community addressed this challenge mainly by proposing novel detection technologies: most of them are still in the conception phase, a few became experiments but are not yet testing motivated DM models. However, relativistic fluxes of light DM necessarily reach us on Earth,...
The energy spectra of particles produced from dark matter (DM) annihilation or decay are one of the fundamental ingredients to calculate the predicted fluxes of cosmic rays and radiation searched for in indirect DM detection. We revisit the calculation of the source spectra for annihilating and decaying DM using the Vincia shower algorithm in Pythia to include QED and QCD final state radiation...
Although Dark matter (DM) is one of the cornerstones of fundamental physics and cosmology, so far it has evaded all the attempts to unveil its nature. A standard way to directly probe DM particles is to search for their scatterings with nucleons in underground detectors. However, in case of DM particles with sub-GeV masses, the direct-detection technique is hampered by the low nucleon recoil...
I will present PEANUTS (Propagation and Evolution of Active NeUTrinoS), an open-source Python package for the automatic computation of solar neutrino spectra and active neutrino propagation through Earth. PEANUTS is designed to be fast, by employing analytic formulae for the neutrino propagation through varying matter density, and flexible, by allowing the user to input arbitrary solar models,...
I discuss several connections between black hole phenomenology and dark matter searches. In the first part of the talk, I consider the idea that black holes of primordial origin constitute a portion of the dark matter that permeates the Universe, and explore the consequences of this idea in a cosmological context, discussing the upper limit on their abundance obtained by analyzing the angular...
Primordial Black holes with mass of 10^15 g should have been evaporated by now giving potentially access to the physics of the Early Universe.
In particular, the presence of PBH could have impacted the process of leptogenesis in different ways depending on the mass and so on the temperature of the PBHs. We present the impact of the non-standard cosmology driven by the presence and the...
It has been discussed that primordial black holes (PBHs), as impurities in the early universe, may have played an important role in the cosmological first-order phase transition (FOPT). Assuming that vacuum bubbles nucleate only around the PBHs, we discuss an unique phenomenology of FOPT. If the number of PBHs within one Hubble volume is smaller than unity at the time of bubble nucleation,...
One of most important issue in Astrophysics is the achievement of a robust understanding of the sequence of processes that contributed to the building up of the Milky Way. This is obviously important not only "on a local scale" in order to recover the history of formation and evolution of the Galaxy, but also, more in general, for understanding
the formation process of spiral galaxies. In the...
The (in)famous method of "Rotation Curves" has informed us for decades about the mass structure of disk galaxies. Does modern technology allow us to hope for a more informative method? I will describe some recent work that hints towards a positive answer.
https://arxiv.org/abs/2111.08725
We analyze the phase transition in improved holographic QCD to obtain an estimate of the gravitational wave signal emitted in the confinement transition of a pure SU(N) Yang-Mills dark sector.
