WIAS Preprint No. 2836, (2021)

Traveling fronts in a reaction-diffusion equation with a memory term



Authors

  • Mielke, Alexander
    ORCID: 0000-0002-4583-3888
  • Reichelt, Sina

2020 Mathematics Subject Classification

  • 35K55 35K57 35C07

Keywords

  • Strong comparison principle, FitzHugh--Nagumo equation, estimates for wave speed, exponentially decaying memory kernels, two-scale homogenization

DOI

10.20347/WIAS.PREPRINT.2836

Abstract

Based on a recent work on traveling waves in spatially nonlocal reaction-diffusion equations, we investigate the existence of traveling fronts in reaction-diffusion equations with a memory term. We will explain how such memory terms can arise from reduction of reaction-diffusion systems if the diffusion constants of the other species can be neglected. In particular, we show that two-scale homogenization of spatially periodic systems can induce spatially homogeneous systems with temporal memory. The existence of fronts is proved using comparison principles as well as a reformulation trick involving an auxiliary speed that allows us to transform memory terms into spatially nonlocal terms. Deriving explicit bounds and monotonicity properties of the wave speed of the arising traveling front, we are able to establish the existence of true traveling fronts for the original problem with memory. Our results are supplemented by numerical simulations.

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