Impacts of WIMP dark matter upon stellar evolution: main-sequence stars

TL;DR

This paper models how WIMP dark matter affects main-sequence stars, showing significant impacts on stellar structure and evolution, especially near supermassive black holes, with potential energy contributions up to 100 times that of hydrogen fusion.

Contribution

It provides detailed stellar models incorporating WIMP effects across various masses and metallicities, and analyzes realistic orbital scenarios near black holes.

Findings

WIMP annihilation can dominate stellar energy output near galactic centers.

Elliptical orbits significantly increase WIMP capture and annihilation rates.

WIMP effects can cause stars to have energy outputs vastly exceeding hydrogen fusion.

Abstract

The presence of large amounts of WIMP dark matter in stellar cores has been shown to have significant effects upon models of stellar evolution. We present a series of detailed grids of WIMP-influenced stellar models for main sequence stars, computed using the DarkStars code. We describe the changes in stellar structure and main sequence evolution which occur for masses ranging from 0.3 to 2.0 solar masses and metallicities from Z = 0.0003-0.02, as a function of the rate of energy injection by WIMPs. We then go on to show what rates of energy injection can be obtained using realistic orbital parameters for stars near supermassive black holes, including detailed considerations of dark matter halo velocity and density profiles. Capture and annihilation rates are strongly boosted when stars follow elliptical rather than circular orbits, causing WIMP annihilation to provide up to 100 times the energy of hydrogen fusion in stars at the Galactic centre.