Special Session 25: 

Existence of traveling wave solutions to a nonlocal scalar equation with sign-changing kernel

Hiroshi Ishii
Hokkaido University, Department of mathematics
Japan
Co-Author(s):    Shin-Ichiro Ei, Jong-Shenq Guo, Chin-Chin Wu
Abstract:
In recent years, the mathematical models with nonlocal interactions have been proposed in various fields: material science, neural fields, pattern formation problem and so on. A nonlocal interaction is given by the convolution with the suitable integral kernel, so its mathematical model is described by the integro-differential equations. A typical example of a kernel in the neural fields is the Mexican hat type function. In the case that the kernel is non-negative, several studies have reported the existence and stability of traveling wave solutions. However, few are known about the existence of traveling wave solutions in the case of sign-changing kernels. Our study revealed the existence of traveling wave solutions connecting the unstable state and the stable state to a nonlocal scalar equation with sign-changing kernel. In this talk, we first introduce a new notion of upper-lower-solution for the equation of wave profile for a given wave speed. We construct two different pairs of upper-lower-solutions and use Schauder`s fixed point theorem to obtain traveling waves for a continuum of wave speeds under some assumptions. Finally, we analyze wave profiles by showing the limit of the both-hand tails.