May 6 – 10, 2024
Europe/Rome timezone

On the impact of lensing on standard sirens measurements

May 6, 2024, 4:00 PM
Room 2.1 (MECC)

Room 2.1


Presentation Observational Science Board (OSB) OSB


Gravitational Waves (GWs) emitted by merging binaries of compact objects, when accompanied by an electromagnetic detection, can be used as “standard sirens” to probe the distance-redshift relation and the standard model of cosmology. However, we expect GW signals to be bent by the intervening matter field during their trajectory towards our detectors, a well-known phenomenon called gravitational lensing. This induces modifications on the measurement of the luminosity distance compared to that in a homogeneous universe. In this talk, I will present how lensing can impact the power of standard sirens for cosmological and astrophysical studies, in the scenario of third-generation ground-based GW detectors, in particular the Einstein Telescope. Treating lensing as a systematic error, I will point out that it can induce a bias in the estimation of the cosmological parameters and quantify it in relation to the characteristics of a catalog of future GW events. For our fiducial scenario, I will show evidence that lensing bias can be comparable to, or greater than, the forecasted statistical uncertainty of the cosmological parameters. Moreover, I will also discuss the impact of lensing on the neutron star mass distribution inferred from events without an electromagnetic counterpart. I will conclude by presenting some mitigation strategies that can be adopted in the data analysis.

Primary author

Sofia Canevarolo


Dr Elisa Chisari (Utrecht University) Loek van Vonderen

Presentation materials