The time perturbations of gravitational waves in asynchronous gauges
Stefano Bondani (Università dell'Insubria)
Tuesday 30/04/2024 @ 14:00, Sala Antonio Sollima (IV piano Battiferro)
Gravitational Waves (GWs) influence time as well as space: the rate of local clocks is in principle affected by the perturbation carried by a GW. In other words, physical time - as the quantity measured by local clocks - follows the amplitude oscillations of the GW, and is expected to slow down and accelerate in phase with the wave’s periodic signal. The theory requires moving outside of the (synchronous) transverse-traceless (TT) gauge towards a more appropriate asynchronous gauge, which makes the desynchronization of clocks explicit, rather than being reabsorbed into the canonical +,x polarizations. In our work we provided an entirely innovative approach to the detectability of GWs via the use of differential time measurements of sufficient precision, not related to the integral measurement of photon paths, as performed by any extended interferometer. Because a GW will affect the rate of physical time both for the observed and the observer's clocks, a second challenge is to disentangle the GW-affected time interval from its own measurement. I will present the theoretical and experimental roadmap concepts behind and ahead of this new and original research. I will show the classes of astrophysical sources already available for detection with currently available technologies in the relevant fields (mainly high precision timing). I will further explore the specific challenges faced when aiming at different GW frequency bands, and how this could be our best shot in the immediate future at detecting intermediate mass black hole mergers