Speaker
Description
High-energy cosmic particles are excellent portals to the possible violation of Lorentz (LV) and/or CPT symmetry from underlying (still elusive) quantum gravity (QG). Given that recent studies of energetic photon (or neutrino) events emitted from (or, associated with) gamma-ray bursts suggest possibilities of LV speed variations that increase linearly with energy, with subluminal propagation of photons but (plausibly-)CPT-violating propagation of neutrinos in cosmic space, I propose string/D-brane theory inspired space-time foam as a viable framework to account for these indications, in a way consistent with various astrophysical data available today. Constraints from recent measurements of LHAASO on the PeV gamma-rays in the (direction of) Cygnus and that arriving from the Crab Nebula to (superluminal) LVs in the electromagnetic and electron/positron sectors, respectively, are highlighted. All of these results lend support to the space-time foam models within brane theories.
