Terrestrial and Martian Heat Flow Limits on Dark Matter

TL;DR

This paper refines limits on dark matter properties by analyzing heat flow constraints on Earth and Mars, considering detailed planetary composition and various dark matter interaction models, to better understand dark matter's potential effects on planetary heat output.

Contribution

It provides improved limits on dark matter-nucleon scattering cross sections for a wide mass range, incorporating detailed planetary models and expanded interaction types, extending previous constraints to Mars.

Findings

Earth and Mars heat bounds are less restrictive for low self-annihilation cross sections.

The study includes spin-dependent and isospin-independent dark matter interactions.

Enhanced limits are established across a broad dark matter mass spectrum.

Abstract

If dark matter is efficiently captured by a planet, energy released in its annihilation can exceed that planet's total heat output. Building on prior work, we treat Earth's composition and dark matter capture in detail and present improved limits on dark matter-nucleon scattering cross sections for dark matter masses ranging from 0.1 to $10^{10}$ GeV. We also extend Earth limits by applying the same treatment to Mars. The scope of dark matter models considered is expanded to include spin-dependent nuclear interactions including isospin-independent, proton only, and neutron only interactions. We find that Earth and Mars heating bounds are alleviated for dark matter s-wave self-annihilation cross sections $\lesssim 10^{-44}~{\rm cm^2}$.