Location: Multifunctional Hall on the 5th floor Meeting time: 2021/06/01 14:00-15:00 (CST)
Speaker: Longlong Feng (Sun Yat-sen University)
Exploring the weakest and the strongest gravity by twisted light
Longlong Feng
Abstract
Black holes and gravitational waves are two important predictions of classical general relativity, and are thus the crucial tests of gravitation theories. In a rotating gravitational field produced by a Kerr black hole, the coupling between the macroscopic rotation of black hole and the angular momentum of photon can not only distort the orbital motion of the photon, and also produces an additional nor-integrable phase, leading to the wavefront distortion of the light coming from near the black hole. On the other hand, it was found that there is a dipole interaction between twisted lights and gravitational waves, which make photos undergoing dipole transitions between different orbital-angular-momentum eigenstates. In this talk, I will discuss these two effects and their astronomical implications, in particular the detection of strongest gravitational fields produced by spinning black holes and the weakest gravitational fields in gravitational waves.
Bio
Feng Longlong, professor at the School of Physics and Astronomy, Sun Yat-sen University, winner of the Ministry of Finance’s “Foreign Talents Program (Chinese Academy of Sciences Hundred Talents Program), National Distinguished Youth Fund”, and enjoys the special government allowance of the State Council. Graduated from the Department of Physics, University of Science and Technology of China in 1982. Obtained a Ph.D. in Astronomy from Nanjing University in 1990; once taught at the University of Science and Technology of China and the Purple Mountain Observatory, and has long been engaged in the research of relativistic astrophysics, galactic astronomy and cosmology. Currently, he is in charge of the key project of the National Foundation of China, “Star-forming galaxies” Baryon Cycle and Dynamics Evolution: Analytical and Numerical Simulation Research” and the key research and development project of the Ministry of Science and Technology “Research on Physics and Astronomy of Dense Celestial Wave Sources for Space Gravitational Wave Detection”.