# Search for domain wall dark matter with atomic clocks on board global positioning system satellites

## TL;DR

This study uses 16 years of GPS atomic clock data to search for domain wall dark matter, setting new constraints on their interactions with standard model particles.

## Contribution

It introduces a novel method of using GPS satellite atomic clocks as a large-scale detector for topological defect dark matter, improving existing limits.

## Key findings

- No evidence of domain wall dark matter was found.
- Constraints on quadratic scalar couplings were significantly improved.
- GPS data can serve as a sensitive detector for macroscopic dark matter objects.

## Abstract

Cosmological observations indicate that 85% of all matter in the Universe is dark matter (DM), yet its microscopic composition remains a mystery. One hypothesis is that DM arises from ultralight quantum fields that form macroscopic objects such as topological defects. Here we use GPS as a ~ 50,000 km aperture DM detector to search for such defects in the form of domain walls. GPS navigation relies on precision timing signals furnished by atomic clocks hosted on board GPS satellites. As the Earth moves through the galactic DM halo, interactions with topological defects could cause atomic clock glitches that propagate through the GPS satellite constellation at galactic velocities ~ 300 km/s. Mining 16 years of archival GPS data, we find no evidence for DM in the form of domain walls at our current sensitivity level. This allows us to improve the limits on certain quadratic scalar couplings of domain wall DM to standard model particles by several orders of magnitude.