Inelastic Dark Matter As An Efficient Fuel For Compact Stars

TL;DR

Inelastic dark matter particles can be captured and annihilated in compact stars at high rates, potentially preventing white dwarfs in dense dark matter environments from cooling below a few thousand Kelvin, offering a new observational test.

Contribution

This paper proposes that inelastic dark matter can significantly influence the thermal evolution of white dwarfs, providing a novel method to test dark matter models through astrophysical observations.

Findings

Old white dwarfs in high dark matter density regions may remain warmer than expected.

Observations of white dwarf temperatures can constrain inelastic dark matter properties.

Inelastic scattering enhances dark matter capture rates in compact stars.

Abstract

Dark matter in the form of weakly interacting massive particles is predicted to become gravitationally captured and accumulate in stars. While the subsequent annihilations of such particles lead to the injection of energy into stellar cores, elastically scattering dark matter particles do not generally yield enough energy to observably impact stellar phenomenology. Dark matter particles which scatter inelastically with nuclei (such that they reconcile the annual modulation reported by DAMA with the null results of CDMS and other experiments), however, can be captured by and annihilate in compact stars at a much higher rate. As a result, old white dwarf stars residing in high dark matter density environments can be prevented from cooling below several thousand degrees Kelvin. Observations of old, cool white dwarfs in dwarf spheroidal galaxies, or in the inner kiloparsec of the Milky Way, can thus potentially provide a valuable test of the inelastic dark matter hypothesis.