报告题目：Transition Fronts for Delayed Reaction Diffusion Equations in Time Almost Periodic Media

报 告 人：王智诚教授兰州大学

报告时间：2023年9月28日（周四）下午14:30

活动地点：腾讯会议：288 419 424（密码：0928）

邀 请 人：黄明迪

报告人简介

王智诚，兰州大学伟德国际BETVlCTOR教授，博士生导师。2007年在兰州大学获理学博士学位，2010年入选教育部新世纪优秀人才支持计划，2011和2019年分别获得甘肃省自然科学二等奖，2016年入选甘肃省飞天学者特聘教授，主持多项国家自然科学基金面上项目和重点项目。目前担任International J. Bifurc. Chaos 等杂志的编委（Associate editor）。主要成果发表在Trans. AMS、Arch. Rational Mech. Anal.、SIAM J. Math. Anal.、SIAM J. Appl. Math.、JMPA、Calc. Var. PDE、JDE、Nonlinearity等国际权威杂志上。

报告摘要：This talk is concerned with propagation phenomena in nonlocal delayed reaction-diffusion equations in time almost periodic media. Firstly we introduce the notion of transition semiwaves for the equation. Then we study properties of exponentially decaying solutions for the corresponding linear problem. Moreover, by constructing appropriate upper and lower solutions and using comparison arguments, we show that no matter the birth rate function is monotone or not, there is a critical wave speed such that a transition semiwave exists as soon as the mean value of wave speed is greater than this critical speed. Some spreading properties for solutions of the Cauchy problem are also established. Finally, a brief discussion is given to show that the critical speed obtained in the present paper coincides with the minimum speed observed by others for some special cases.