GPS.DM: Using GPS as a Dark Matter observatory

The GPS.DM collaboration analyzes navigational satellite and terrestrial atomic clock data looking for signatures of exotic physics. In particular, the collaboration searches for transient variations of fundamental constants correlated with the Earth’s galactic motion through the dark matter halo.

Our most recent results have just been published in Nature Communications (Open Access)

Cosmological observations indicate that 85% of all matter in the Universe is dark matter, yet its microscopic composition remains a mystery. One hypothesis is that dark matter arises from ultralight quantum fields that form macroscopic objects such as topological defects (see our previous post here for a brief overview of this topic).
In our recent work, we used the GPS constellation as a ~ 50,000 km aperture dark matter detector to search for such defects in the form of domain walls.

 

As the Earth moves through the galactic dark matter halo, periodic interactions with topological defects (dark matter "clumps") could cause atomic clock glitches that propagate through the GPS satellite constellation at galactic velocities

GPS navigation relies on precision timing signals furnished by atomic clocks hosted on board GPS satellites. As the Earth moves through the galactic dark matter halo, interactions with topological defects could cause atomic clock glitches that propagate through the GPS satellite constellation at galactic velocities ~ 300 km/s, as shown in the figures above.
By mining 16 years of archival GPS data, we found no evidence for dark matter in the form of domain walls at our current sensitivity level. This allowed us to improve the limits on certain quadratic scalar couplings of domain wall dark matter to standard model particles by several orders of magnitude.

Limits on the energy-scale for the coupling of domain wall dark matter to electromagnetism. The red line shows the potential future reach of our technique.

Popular science articles

These serve as a nice non-technical introduction to our work.

Previous publications

See also our previous related posts:

Members of collaboration (in alphabetical order):

  • G. Blewitt (U. Nevada. Reno)
  • A. Derevianko (U. Nevada, Reno)
  • M. Pospelov (UBC and Perimeter Institute)
  • J. Sherman (NIST-Boulder)

Postdoctoral scholar(s): B. Roberts

Graduate student(s): A. Rollings, C. Dailey

Undergraduate student(s): I. Tralmer

Former members: K. Lane, M. Murphy, N. Lundholm, W. Williams

Supported by the U.S. National Science Foundation.