Dark Matter Substructure under the Electron Scattering Lamppost

TL;DR

This paper explores how local dark matter substructure, suggested by Gaia data, influences electron scattering experiments and how future experiments can detect or constrain such substructure.

Contribution

It introduces a framework linking dark matter substructure to electron scattering signals and shows how experiments can probe substructure even if it is a minor component.

Findings

Dark matter substructure affects scattering spectra and modulation signals.

Future experiments can detect or constrain substructure fractions.

Substructure can be probed even when sub-dominant.

Abstract

We study the mutual relationship between dark matter-electron scattering experiments and possible new dark matter substructure nearby hinted by the Gaia data. We show how kinematic substructure could affect the average and modulation spectra of dark matter-electron scattering in semiconductors, and the discovery reaches of future experiments with these targets. Conversely, we demonstrate how future data could probe and constrain the substructure dark matter fraction, even when it constitutes a sub-dominant component of the local dark matter density.