High accuracy on $H_{0}$ constraints from gravitational wave lensing events
In this seminar I will present my latest paper where we suggest a method to constrain the cosmological background, and the Hubble constant in particular, by future observations of gravitationally lensed radiation emitted by a single source in both the gravitational wave and the electromagnetic regimes.
The lensing of the gravitational wave radiation, in fact, can leave a clear imprinting in the corresponding waveform and we analyzed if such kind of measurements can be successfully employed to better constrain the cosmological background. We studied the impact of different cosmological parameters on the value of the arrival time delay due to gravitational lensing, given different gravitational wave frequencies, mass models of the lens, and redshifts and positions (with respect to the lens) of the source.
I will show how even a single multi-messenger lensing event could provide us with an uncertainty on $H_0$ two orders of magnitude smaller than the uncertainties given by present independent probes.