Search for Exotic Physics Modality in Multi-Messenger Astronomy with the Global Positioning System
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Authors
Sen, Arko Pratim
Issue Date
2025
Type
Dissertation
Language
en_US
Keywords
Atomic clocks , Beyond Standard Model physics , Data analysis , Global Positioning System , Multi-messenger astronomy , Statistics
Alternative Title
Abstract
We investigate a new way to search for exotic physics using multi-messenger astronomy. Here, exotic physics refers to theories beyond the now well-established Standard Model (SM) of elementary particles. Multi-messenger astronomy is the coordinated observation of different classes of signals from the same astrophysical source.When massive compact objects such as black holes or neutron stars merge, then along with gravitational waves (GWs), they may also release bursts of hypothetical scalar particles/fields which are ultralight, with masses $\ll 1\,\text{eV}/c^2$, where $c$ is the speed of light. These hypothetical fields, referred to here as exotic low-mass fields (ELFs), would travel slightly slower than the GWs which propagate at the speed of light. The ELFs are hypothesized to transiently alter the fundamental constants of nature and thereby vary the atomic transition frequencies. If so, ELFs could be detected using atomic clocks on board the Global Positioning System (GPS) satellites. This work specifically focuses on the network of rubidium atomic clocks, which make up the majority of the GPS constellation. If ELFs interact with the known SM matter by temporarily altering fundamental constants, they would leave a distinct, “anti-chirp” timing signature across the GPS clock network. We search for ELF bursts temporally correlated with the GW trigger:~GW170817, detected by the LIGO–Virgo collaboration on August 17, 2017. Clock data from the GPS constellation are analyzed in a window bracketing this LIGO–Virgo GW trigger, and we construct correlated observables sensitive to propagating disturbances with near-luminal velocities. No statistically significant signatures are found. We translate this null result into improved constraints on the coupling strengths of candidate dark-sector fields to atomic clocks. These constraints surpass previous astrophysical bounds by several orders of magnitude, tightening the parameter space available for models of ultralight exotic scalar fields.