Jishnu Suresh (Henri Poincaré fellowship) Gravitational Wave Symphony; Being Sensitive is Crucial!

As we enter the second phase of the fourth observing run of the Advanced LIGO, Virgo, and KAGRA detector network, we are thrilled to register nearly eighty gravitational-wave event candidates. This event rate, with detections occurring every two to three days, is remarkable. These detections have deepened our understanding of black holes and neutron star populations. Moreover, they've empowered us to make a more robust assessment of the gravitational wave background, which emerges from the incoherent superposition of many unresolvable signals in the universe. Although these backgrounds are individually undetectable, they can be detected as a collectivity via their common influence on multiple detectors. This phenomenon can be likened to a musical symphony where each binary black hole or neutron star represents a soloist, and the collective hum offers a glimpse into our universe's primordial past. In this seminar, I will discuss the current status of the searches for such gravitational wave backgrounds.