Abstract
Astrometric weak gravitational lensing is a powerful probe of the distribution of matter on sub-Galactic scales, which harbor important information about the fundamental nature of dark matter. We propose a novel method that utilizes angular power spectra to search for the correlated pattern of apparent motions of celestial objects induced from time-dependent lensing by a population of Galactic subhalos. Application of this method to upcoming astrometric datasets will allow for the direct measurement of the properties of Galactic substructure, with implications for the underlying particle physics. We show that, with near-future astrometric observations, it may be possible to statistically detect populations of cold dark matter subhalos, compact objects, as well as density fluctuations sourced by scalar field dark matter. Currently unconstrained parameter space will already be accessible using upcoming data from the ongoing Gaia mission.
9 More- Received 23 March 2020
- Accepted 17 June 2020
DOI:https://doi.org/10.1103/PhysRevD.102.023026
© 2020 American Physical Society
Physics Subject Headings (PhySH)
synopsis
Searching for Dark Matter in Distorted Starlight
Published 22 July 2020
Statistical studies of the motions of millions of stars may reveal the subtle imprint of dark matter.
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