GPS.ELF: Multi-messenger astronomy search for exotic low-mass field emission from the binary neutron star merger (GW170817) using GPS atomic clocks*

Exotic low-mass fields (ELF) can be potentially emitted from powerful astrophysical events, such as binary neutron star and binary black hole mergers. This leads to an intriguing possibility for a novel, exotic physics, modality in multi-messenger astronomy [Nature Astronomy 5, 150 (2021)]. In our ELF search, we use the data from atomic clocks of the Global Positioning System (GPS) making it a quantum sensor network. It is expected that ELFs imprint an anti-chirp transient across the GPS sensor network, conditioned on the LIGO gravitational wave detection. As ELFs interact with the standard model particles, they induce a transient change in the fundamental constants, like the fine structure constant and masses of fermions. Atomic clocks are sensitive to the change in the fundamental constants. In this poster we demonstrate our use of a running median subtraction filter (RMSF) on the non-stationary GPS data. This RMSF removes any time-varying background clutter without distorting a transient signal, if the running window size is chosen appropriately. Our search targets the August 17, 2017, GW170817 binary neutron star merger event detected by LIGO. We present the progress of our search for such feebly interacting ELFs using GPS data to which we apply RMSF to make the data approximately stationary and use a suitable statistic to set limits on the coupling constant as a function of the ELF parameters.