PhD defense by Tetyana Pitik

High Energy Neutrino Emission from Astrophysical Transients

The cosmic phenomena involving extreme energies remain enigmatic, with many events still requiring complete understanding. Investigating these phenomena solely through electromagnetic radiation can pose significant challenges. Photons interact with matter and radiation in the sites where they are produced and during their journey to Earth, with consequent degradation of the information they carry. Furthermore, even if the electromagnetic signal should reach Earth, the encoded information could be ambiguous, challenging our chances to decipher the underlying source physics. In contrast, neutrinos can be produced in the same sources abundantly as a byproduct of particle acceleration. Due to their weakly interacting nature, neutrinos can travel undisturbed through space, providing valuable complementary information. This thesis aims to harness the potential of neutrinos with TeV-PeV energy to provide insight into the physics of two extremely bright transient phenomena: long gamma-ray bursts and superluminous supernovae. Our findings confirm that high-energy neutrinos stand as invaluable cosmic messengers, holding the promise to address numerous open questions on the high-energy Universe. The potential of neutrinos will be fully unleashed through upcoming multi-messenger programs.

The thesis is available for consultation.

Supervisor: Irene Tamborra

Opponents: Kumiko Kotera, Foteini Oikonomou and Martin Pessah