Transition Fronts for Delayed Reaction Diffusion Equations in Time Almost Periodic Media

讲座时间 Datetime: 2022年9月12日，星期一，15:00-16:00

地点 Venue: 腾讯线上会议：309-476-718

主持人 Host：唐德

报告人 Speaker: 王智诚 

单位 Affiliation: 兰州大学

报告摘要 Abstract:

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.