Time: Friday, Dec. 4, 10:00 am
Venue: Rm. 413, Bld. 11#, Yuquan Campus & Ding Talk Video Conference (Group "Plasma Seminar")
Speaker: 张宇
Title: QED Cascade in Vacuum Induced by Fast Radio Bursts
Abstract: Fast radio bursts (FRBs) are bright coherent bursts of radio waves with durations roughly at the millisecond scale. It arrived from the extragalactic universe while the generation mechanism is not yet clear. The first recently observed FRB in the Milky Way reveals it origin from magnetar (a highly magnetized neutron star). Based on the observational characteristics of FRBs, we speculated that the original form of FRBs radiation is like a single-period, linearly polarized Gaussian pulse with quantum electrodynamics (QED) field strength. The nonlinear Compton scattering and Breit-Wheeler process are added in one dimensional particle in cell code to simulate the propagation of original FRBs radiation in almost vacuum (only a few gamma photons existed ) to explore the critical field strength for such a pulse to transport. An introduction of FRBs and our related simulation work would be given in this talk.