[CUSPEA学者系列讲座] [赖东(Cornell U.)] Circumbinary Accretion: From Supermassive Binary Black Holes to Circumbinary Planets


Dong Lai (赖东), Cornell University

November 1, Monday, 9:30-11:00 

Zoom会议号: 930 130 2021    密码: 202111


Circumbinary disks have been observed in a number of young stellar systems, and are the birth place for circumbinary planets found by transit surveys. They are also expected to exist around supermassive black hole binaries as a consequence of accretion from the interstellar medium following galaxy mergers. I will discuss recent works on numerical modeling of circumbinary accretion, focusing short-term and long-term variabilities, and angular momentum transfer between the disk and the binary -- the result suggests that the long-standing notion of binary orbital decay driven by circumbinary disk may be problematic. Implications for planet formation/migration around stellar binaries will be noted. I will also discuss the dynamics and evolution of inclined/warped disks in binaries and connect with recent observations of protoplanetary disks and circumbinary planets.

About the speaker

Dong Lai is a Professor of Astrophysics. He received B.S. degree with USTC, and Ph.D. in physics from Cornell in 1994, and was a postdoctoral fellow at Caltech. He joined the faculty of the Astronomy Department at Cornell in 1997. His current research is in theoretical astrophysics, focusing on exoplanets, compact objects (neutron stars, black holes and white dwarfs), and astrophysical (particle and fluid) dynamics in general. He has held visiting appointments IAS, Harvard, CITA etc and several universities/observatories in China. He has been awarded A.P. Sloan fellowship, Simons fellowship, and Miller Visiting Professorship from UC Berkeley.