Marco Roncadelli: "Hints at new physics from very-high-energy astrophysics"

Wednesday 11 Jun 2025, 14:30 → 16:00 Europe/Rome

Aula Rasetti

The gamma-ray burst GRB 221009A, observed on October 9, 2022, at redshift z = 0.151, is the most luminous GRB ever recorded. Photons with energies above 12 TeV have been detected by the LHAASO collaboration, and a photon with energy E = 251 TeV was reported by Carpet-2. A recent, more detailed analysis by the Carpet-3 collaboration confirms the robustness of this extreme event, now estimated at approximately 300 TeV. However, within the framework of conventional physics, photons with energies ≳10 TeV are expected to be strongly attenuated by interactions with the extragalactic background light (EBL), making their detection from such distances highly improbable. Previous studies have shown that photon-ALP oscillations could enable the propagation of the LHAASO photons. In this talk, we discuss how the Carpet-3 photon can instead be explained by scenarios involving Lorentz invariance violation (LIV), providing a compelling case for new physics in the very-high-energy regime.