I review some anomalies in the measured fluxes of Galactic charged cosmic rays and the associated non-thermal emission (in particular: high-energy positrons, features in the proton spectrum, gamma-ray hardening towards the Galactic centre, 511 keV line). These anomalies may point towards interesting aspects of cosmic-ray production and propagation or new physics.
The diffuse astrophysical neutrino flux measured in the very high energy range introduced unresolved issues about the origin of these events and underlined as a viable solution the multi-component scenario. Recent studies show that galaxies with high star formation rate (above teens Mo/year) can be responsible of a seizable fraction of the observed astrophysical flux.
Despite their low...
The relic $\nu$ background (R$\nu$B) is the `holy grail’ of neutrino physics and it is also the only known Dark Matter subcomponent. Yet, it has so far escaped detection attempts, mainly due to the very low energies and very weak cross-sections involved in the detection channels. In this talk, I will describe the mechanism by which ultra-high energy (UHE) cosmic rays, stored in cosmic...
As the WIMP paradigm for Dark Matter (DM) is increasingly challenged by the non detection of DM, this motivates the investigation of other DM mass ranges.
In the latest years the focus shifted towards the study of sub-GeV DM, which direct detection is limited by the low energy recoil that it imprints on nuclei. However, the assumption that it has a non zero interaction cross section with the...
While it is way too early to make a final judgement, it is noteworthy that searches at LHC and direct detection experiments reported null results, therefore boosting the ever growing interest in sub-GeV dark sector candidates. Owing to their high temperature and density, the cores of proto-neutron stars, remnant of core-collapse supernovae and neutron star mergers, can be factories of...
Primordial Black holes (PBHs) are hypothetical black holes formed in the earliest times of the Universe, as a result of inflationary scenarios or physics beyond the Standard Model. These intriguing objects have attracted significant attention over the last decade, especially in the context of dark matter and detectability of the Hawking radiation from PBH evaporation. Recent studies have...
PBHs in the so called "asteroid mass" range may still constitute all of the relic DM. The low mass end of this range is constrained by the non-observation of extra-galactic gamma rays. If asteroid mass PBHs form hot spots, one should expect firstly some attenuation of the primary gamma ray signal by the hot spot, and secondly a secondary component from the hot spot. Re-examining these...
I propose to discuss a scenario where superheavy Dark Matter (DM) can be generated from ultralight Primordial Black Holes in the early universe. If we go to a bit more fundamental level (e.g., think of how the DM becomes massive after a phase transition), we can associate the scenario with gravitational waves and their possible detection with the Pulsar Timing arrays (PTAs). It might be an...
We present a detailed study of the production of dark matter in the form of a sterile neutrino via freeze-in from decays of heavy right-handed neutrinos. Our treatment accounts for thermal effects in the effective couplings, generated via neutrino mixing, of the new heavy neutrinos with the Standard Model gauge and Higgs bosons and can be applied to several low-energy fermion seesaw scenarios...
This project aims to explore the use of novel machine learning methods to estimate dark matter distributions around galaxies, offering a more flexible approach compared to traditional techniques. Conventional methods, such as analysing galaxy rotation curves, depend on numerous assumptions—many of which may not hold true for real galaxies, leading to potential inaccuracies in dark matter...
A recent anlysis of GAIA's data suggest claims to have seen the beginning of the decline of the Milky Way's rotation curve.
This would have interesting implications for the Milky Way mass determination, if true.
I propose a critical assessment of the the analysis, followed by an independent analysis of of the MW mass distribution in light of GAIA's new data.
