Glimpsing Physics of Nano-Hz Gravitational Waves in Neutrinos from Core-Collapse Supernovae

TL;DR

This paper explores the potential connection between nano-Hz gravitational waves and phase transitions in the early universe, proposing that supernova neutrino signals could reveal new physics beyond the Standard Model.

Contribution

It introduces a novel scenario linking supernova neutrino spectra to cosmological phase transitions and discusses how future observations could confirm this connection.

Findings

Potential imprint of early universe phase transitions on supernova neutrinos

Future pulsar timing array data could confirm the primordial origin of gravitational waves

Supernova neutrino observations may reveal physics beyond the Standard Model

Abstract

The growing evidence for nano-hertz gravitational waves, from NANOGrav and other observations, may be pointing to a cosmological first-order phase transition at temperatures of $\mathcal{O}(10-100)\;\mathrm{MeV}$. Such an interpretation requires dynamics beyond the Standard Model in this energy range. If so, it may well be the case that core-collapse supernova explosions would recreate the first-order phase transition leaving a unique imprint on the spectrum of neutrinos emitted in the initial few seconds. This scenario is also suggestive of a low-mass seesaw mechanism to explain neutrino masses. We outline the prospects for future observations of Galactic supernovae to uncover the signals of this scenario, which could get further confirmation with additional pulsar timing array data establishing the primordial origin of the observed nano-hertz gravitational waves.