Results of the search for topological dark matter using atomic clock data from the global positioning system

We use the Global Positioning System (GPS), comprised of nominally 32 atomic microwave clocks, as a 50,000 km-diameter network of quantum sensors capable of searching for exotic physics, such as “clumpy” dark matter (DM). We search for ultralight, self-interacting quantum fields that form macroscopic DM objects, e.g., 2D domain walls. Encounters between the GPS constellation and 2D domain walls would cause a sequence of atomic clock perturbations, imprinting a certain sweeping signature across the network. Recently, we have performed a search for these DM signatures, investigating 20 years of archival GPS atomic clock data. Our statistical analysis uses two filters: (i) a signal-to-noise (SNR) filter and (ii) a χ² filter. The SNR threshold imposes a rate of false positives to one in 100 years, and the χ² threshold eliminates poor template matching for DM candidate events. Finally, events that pass both filters undergo parameter estimation, where speed and angles of incidence are determined. The results of our GPS.DM search will be presented at the conference.