From A# to Cosmic Explorer: Expanding Astrophysical Horizons with Gravitational Waves

The next decade in gravitational-wave astronomy promises revolutionary advancements in astrophysical discovery through current detectors enhanced by A# upgrades and next-generation observatories like Cosmic Explorer (CE) and the Einstein Telescope (ET). These advancements will push the boundaries of multi-messenger astronomy, enabling precise localization of merger events and facilitating prompt electromagnetic follow-up observations. In this talk, I will explore the immense scientific potential of these observatories—from constraining neutron star physics to mapping the full population of merging black holes across cosmic history, from the epoch of the first stars to cosmic noon. Additionally, CE and ET will open new avenues to probe rare and exotic phenomena, such as black holes formed from the collapse of Population III stars, primordial black holes from the early universe, and signatures of dark matter in compact objects. I will highlight how these next-generation observatories will expand our understanding of compact object populations and provide groundbreaking insights into the fundamental processes that shape the universe.