GGI Post-Doc Day 2025

slides7954.pdf

Heavy Dark Matter candidates with masses around the TeV scale and beyond are notoriously challenging to probe. In this talk, I will show how Indirect Detection can offer valuable insights. First, I discuss recent advances in multi-TeV WIMPs, focusing on the Minimal Dark Matter 5-plet and on how non-perturbative effects such as Sommerfeld enhancement and bound-state formation modify its gamma-ray spectrum. The low-energy part is constrained by Fermi-LAT measurements of the galactic diffuse emission, while the high-energy part of the spectrum is used to estimate the Cherenkov Telescope Array (CTA) reach for dwarf spheroidal galaxies. In the second part, I examine Primordial Black Holes (PBHs) in the 10–10^15 g range. The recently proposed memory burden effect implies that evaporating PBHs stabilize before full decay, reopening a viable PBH dark matter window below 10^15 g. I present the resulting particle fluxes and show that much of this parameter space is within reach of detection.

In recent years, substantial effort has been devoted to revisiting quantum field theory (QFT) through the lens of the Lorentz group, with the hope of exploiting powerful methods developed in the context of conformal field theory (CFT). This program is commonly referred to as Celestial holography. In this talk, we analyse the Hilbert space of asymptotic states in this alternative description, decomposing Wigner’s particle states into unitary irreducible representations (UIRs) of the Lorentz group. We will conclude by examining the implications of this alternative description for QFT, and by highlighting connections with the holographic paradigm of AdS/CFT.

slides7955.pdf

We develop a first-principles formalism, based on the transport equation in the line-of-sight approximation, to link the expected number of muons at neutrino telescopes to the flux of neutrinos at the Earth's surface. We compute the distribution of muons inside Earth, arising from the up-scattering of neutrinos close to the detector, as well as from the decay of taus produced farther away. This framework allows one to account for systematic uncertainties, as well as to clarify the assumptions behind definitions commonly used in the literature, such as the effective area. We apply this formalism to analyze the high-energy muon event recorded by KM3NeT, with a reconstructed energy of 120−60+110 PeV and an elevation angle of (0.54±2.4)°, in comparison with the non-observation of similar events by IceCube. We find a 3.1σ tension between the two experiments, assuming a diffuse neutrino source with a power-law energy dependence. Combining both datasets leads to a preference for a very low number of expected events at KM3NeT, in stark contrast to the observed data. The tension increases both in the case of a diffuse source peaking at the KM3NeT energy and of a steady point source, whereas a transient source may reduce the tension down to 1.6σ. The formalism allows one to treat potential beyond-the-Standard-Model sources of muons, and we speculate on this possibility to explain the tension.