Fast Radio Burst Radiation Mechanism & Cosmology  

报告人简介：(Speaker introduction)

Pawan Kumar obtained his Ph.D degree from California Institute of Technology, Pasadena in 1988 and has been working as a professor at  University of Texas at Austin since 2002.He worked as an assistant professor at MIT in 1992-1996 and a visiting professor at IAS in 1996-2002.  He won Alfred P. Sloan Research Fellow in 1993 and NSF Young Investigator Award in 1994.

His main research interests are gamma-ray bursts, tidal disruption of stars by super-massive black holes,fast radio bursts, helioseismology,tidal interactions & excitation of stellar modes.

报告摘要：（Abstract）

The detection of a Fast radio burst (FRB) in 2007 was a major unexpected discovery in astronomy in decades. Hunting for FRBs and measuring their physical properties have become one of the leading scientific goals in astronomy; CHIME has increasingly become the dominant player in this new field and the FAST telescope in China has made many important contributions to the discovery and study of FRBs. It is well established that many FRBs are located at several billion lightyears from us, and therefore they are the brightest known transients in the universe in the radio band. Using very general arguments, I will show that the radio emission is coherent, the magnetic field strength associated with the source of these events should be 10^{14}Gauss or more. Recently, an FRB was discovered in the Galaxy, and it confirmed that at least some FRBs are associated with magnetars. I will describe my recent work regarding how the FRB radiation is produced. I will describe lensing of FRBs and how that is affected by wave scattering in a turbulent medium. If there is time remaining, I will describe how FRBs can be used as a probe of the baryon distribution in the universe and for investigating the epoch of reionization.