School of Physics Colloquium

Abstract: With the detection of gravitational waves emitted during black hole and neutron star mergers, LIGO has recently opened the field of gravitational wave astrophysics. In this talk I will review the astrophysical processes that may be responsible for the formation of the observed events. The event rate distribution with mass, spins, eccentricity and redshift may be used to discriminate among different processes that lead to black hole mergers. I will show that the standard astrophysical merger pathways are already in tension with LIGO/VIRGO observations. New ideas may be needed to explain the origin of the detected sources. I will discuss the possibility that black hole mergers happen in active galactic nuclei where the interaction with a gaseous disk helps to form binaries, and a combination of dynamical and gas effects facilitate the merger of the binaries. Bio: Prof. Kocsis is a theoretical astrophysicist working on a wide range of topics including gravitational wave astrophysics using LIGO/VIRGO, LISA, and pulsar timing arrays, astrophysical dynamics of dense star clusters, astrophysical general relativity, black holes physics from stellar mass to supermassive scales, accretion disks, disk-satellite interactions, and statistical mechanics. Before coming to Oxford, Prof. Kocsis was a faculty member at Eotvos University, and even earlier, a postdoctoral fellow at the Institute for Advanced Study and at the Harvard Center for Astrophysics. Prof. Kocsis is the PI of the GALNUC project funded by an ERC Starting Grant which strives to develop a comprehensive model to describe the long term behavior of astrophysical multibody systems using multidisciplinary methods.