报告人：高忆先 （东北师范大学）

报告题目：Modal approximation for time-domain elastic scattering from metamaterial quasiparticles.

邀请人：冯晓莉 副教授

报告时间：2022年12月7日下午2：30

腾讯会议ID：294-752-322

报告摘要：This talk aims at quantitatively understanding the elastic wave scattering due to negative metamaterial structures under wide-band signals in the time domain. Specifically, we establish the modal expansion for the time-dependent field scattered by metamaterial quasiparticles in elastodynamics. By Fourier transform, we first analyze the modal expansion in the time-harmonic regime. With the presence of quasiparticles, we validate such an expansion in the static regime via quantitatively analyzing the spectral properties of the Neumann-Poincaré operator associated with the elastostatic system. We then approximate the incident field with a finite number of modes and apply perturbation theory to obtain such an expansion in the perturbative regime. In addition, we give polariton resonances as simple poles for the elastostatic system. Finally, we show that the low-frequency part of the scattered field in the time domain can be well approximated by using the resonant modal expansion with sharp error estimates.

个人简介：高忆先，东北师范大学教授、博士生导师。主要从事动力系统和散射、反散射理论的研究，相关研究成果发表在《Arch. Ration.Mech. Anal.》，《 J. Math. Pures Appl.》《SIAM J. Math.Anal.》，《 J. Differential Equations》等国际权威杂志。