Quasi-normal modes (QNM) describe the return to equilibrium of a perturbed system, in particular the ring-down phase of a black hole merger. In this talk, the speaker will first review QNM of a Schwarzschild black hole. As a globally defined quantity, QNM is highly sensitive to global spacetime structure. For instance, placing a star far away from a black hole alters the QNM spectrum by a huge amount. The speaker and his research team will demonstrate analytically how to identify the QNM spectrum of a localized object from the global QNM. Finally, the speaker will mention some mysterious properties of black hole QNM spectrum in Einstein gravity.
About the speaker
Dr. Sam Wong received his BSc and PhD in Physics from The Hong Kong University of Science and Technology in 2011 and 2017 respectively. He was a recipient of the Croucher Foundation Fellowship in 2017 and a Visiting Scholar at University of Southern Denmark in 2018. He is currently a Postdoctoral Research Fellow at the Department of Physics of Columbia University.
Dr. Wong’s research focuses on theoretical cosmology, particle theory, string theory and supergravity. He conducts research in revealing the early cosmological history to infer the origin and fundamental nature of our universe, in particular, inflationary models and quantum nature of the early universe. He also studies baryon/lepton number violation of the standard model to understand the origin of matter anti-matter asymmetry.
