Neutrino Emission from Helium White Dwarfs with Condensed Cores

TL;DR

This paper investigates how a potential Bose-Einstein condensed state of ions in helium white dwarfs could lead to enhanced neutrino emission, affecting their luminosity and providing a possible observational signature of this exotic phase.

Contribution

It explores the neutrino emission from a hypothesized condensed ion state in helium white dwarfs and its impact on stellar luminosity, proposing a new way to detect this quantum phase.

Findings

Neutrino emission from the gapless mode could significantly increase white dwarf luminosity.

The impact depends on the condensation temperature of the quantum liquid.

Potential observational signatures could confirm the existence of the condensed phase.

Abstract

The possibility that ions in a helium white dwarf star are in a Bose-Einstein condensed state has been explored recently. In particular, it has been argued that the resulting novel quantum liquid has a new kind of quasiparticle excitation with a phonon-like dispersion relation. We investigate the neutrino emission rate due to this gapless state and the resulting impact on the total luminosity of helium white dwarf stars, as a possible observable way of detecting this exotic phase. If the condensation temperature for the quantum liquid state, which is currently not known very precisely, turns out to be high enough, our calculations indicate that neutrino emission due to the gapless mode would make a large contribution to the total luminosity of the helium white dwarf stars.