Physics Graduate Student Symposium

Our next session is July 17th, 2025 at 12:00 PM

Cosmology with Gravitational Wave Standard Sirens: A Multi-Messenger View of Stellar Mergers

Simran Kaur

Third Year, Department of Physics

Gravitational-wave standard sirens are compact binary mergers that offer a direct measurement of luminosity distance, providing a powerful and independent method to probe cosmological parameters, most notably the Hubble constant (H₀). This talk will introduce the methodology of cosmological inference using both bright sirens (with identified electromagnetic counterparts) and dark sirens (statistically associated with galaxy catalogs), and discuss how they contribute to precision cosmology.

The success of this approach relies on a coordinated effort between gravitational wave detectors (such as LIGO and Virgo) and wide-field optical survey telescopes like the Dark Energy Camera (DECam) and the upcoming Vera C. Rubin Observatory. The Dark Energy Survey–Gravitational Waves (DESGW) program exemplifies such coordination by enabling timely electromagnetic follow-up of GW events and contributing to early standard siren measurements.

Looking ahead, simulation efforts are underway to forecast the cosmological power of the Rubin Observatory’s LSST, including expected constraints on H₀. These projections highlight the exciting potential of next-generation surveys to transform gravitational-wave cosmology in the coming decade.

Click here for a full list of PGSS 2025 Speakers