报告题目：GLOBAL DYNAMICS AND PHOTON LOSS IN THE KOMPANEETS EQUATION

报告时间：2023-06-12  16:00-17:00

报告人：Prof. Hailiang Liu , Iowa State University

报告地点：理学院东北楼四楼报告厅（404）

报告摘要：The Kompaneets equation governs dynamics of the photon energy spectrum in certain high temperature (or low density) plasmas. We prove several results concerning the long-time convergence of solutions to Bose–Einstein equilibria and the failure of photon conservation. In particular, we show the total photon number can decrease with time via an out-flux of photons at the zero-energy boundary. The ensuing accumulation of photons at zero energy is analogous to Bose–Einstein condensation. We provide two conditions that guarantee that photon loss occurs, and show that once loss is initiated then it persists forever. We prove that as time tends to infinity, solutions necessarily converge to equilibrium and we characterize the limit in terms of the total photon loss. This talk is based on a joint work with J. Ballew, G. Iyer, D. Levermore and R. Pego.