Gravitational waves, as predicted by Einstein one hundred years ago, are detected by the advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) in September last year. This finding marks the beginning of gravitational-wave astronomy. From now on, we are able to probe our universe using both long-range forces in nature. In the foreseeable future, the gravitational wave astronomy will be exponentially growing, with more detectors targeting gravitational waves at different frequencies and more events detected every week. This will provide us great opportunities but also impose challenges as well. In the first part of my talk, I will discuss the physics of gravitational wave detectors, emphasizing its basic principles and dominant noise sources, as well as ongoing efforts to improve detector sensitivity to fulfill the growing need. In the second half of my talk, I will discuss the astrophysics of gravitational-wave sources - especially compact sources such as black holes and neutron stars. I shall explain the spacetime dynamics, gravitational-wave emission during compact binary mergers and possible electromagnetic radiation from these compact objects. In the next few years with new gravitational-wave observations and possible electromagnetic counterpart measurements, we may dramatically improve our understandings on the astrophysics of these sources.

Bio: Dr. Huan Yang studied in Tsinghua University from 2002 to 2004 and transferred to Caltech afterwards. He obtained his Bachelor degree in 2007 and then worked in a Hedge Fund in Wall street for a year. In 2008 he joined Dr. Yanbei Chen's group in Caltech to study theoretical astrophysics, and obtained his PhD degree in 2013. From 2013 till now he is a postdoctoral fellow at Perimeter Institute for Theoretical Physics. Dr. Yang was a member of the LSC (LIGO Scientific Collaboration) from 2010 to 2014. He received the Housner Award at Caltech in 2007, and the honorable mention in the Thesis Prize by Gravitational-Wave International Committee in 2013. His research areas include relativistic astrophysics, gravitational wave and electromagnetic signatures from black holes, neutron stars and white dwarfs, classical and quantum noise in gravitational wave detectors, quantum measurement, and quantum optomechanics.