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
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.
- Science magazine: Hunting dark matter with GPS data
- Scientific American: Hunting Dark Matter between the Ticks of an Atomic Clock
- Quanta magazine: Ultra-Accurate Clocks Lead Search for New Laws of Physics
- Cosmos magazine: GPS satellites “the largest dark matter detector ever built”
GPS.DM publications
- Search for domain wall dark matter with atomic clocks on board global positioning system satellites, Nature Communications 8, 1195 (2017)
- Hunting for topological dark matter with atomic clocks, Nature Physics 10, 933 (2014),arXiv:1311.1244
- Detecting dark matter waves with precision measurement tools, Phys. Rev. A 97, 42506 (2018),arXiv:1605.09717
- Atomic clocks and dark-matter signatures, J. Phys. Conf. Ser. 723, 12043 (2016)
- Precision measurement noise asymmetry and its annual modulation as a dark matter signature, arXiv:1803.00617
- Search for transient ultralight dark matter signatures with networks of precision measurement devices using a Bayesian statistics method, Phys. Rev. D 97, 083009 (2018), arXiv:1803.10264
- Applying the matched-filter technique to the search for dark matter transients with networks of quantum sensors, arXiv:astro-ph:1908.03320
See also our previous related posts:
- Search for topological dark matter with atomic clocks
- Dark matter search with GPS: Q&A
- A data archive for storing precision measurements [Physics Today]
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): T. Daykin
Graduate student(s): A. Sen
Undergraduate student(s): T. Maddox, K. Pfeffer, Z. Waller
Former members: C. Bradley, C. Dailey, V. Dumont, K. Lane, N. Lundholm, M. Murphy, G. Panelli, B. Roberts, A. Rollings, I. Tralmer, W. Williams
Supported by the U.S. National Science Foundation.
