Special Session 131: Recent progress on singularities formations of some evolution partial differential equations

Critical and subcritical blow-up for the nonlocal shadow limit of the Gierer-Meinhardt system

Hatem Zaag
CNRS and Universite Sorbonne Paris Nord
France
Co-Author(s):    
Abstract:
The Gierer-Meinhardt system is a model for pattern formation based on Turing`s mechanism. Under some conditions, it reduces to a scalar heat equation, with a nonlinearity showing a pure power divided by some non-local term. Depending on parameters, that equation shows two different types of blow-up behavior: - in some subcritical range of parameters, the non-local term converges to a positive constant, leading to some blow-up behavior similar to the classical semilinear heat equation, with power nonlinearity ; - in the critical case, the non-local term converges to infinity, weakening the effect of the pure power nonlinearity. This leads to a new type of blow-up behavior, unknown in earlier literature. In this talk, we construct examples for the two types of behaviors, and give their blow-up profiles. Our method happens to be a non-trivial adaptation of the classical construction method for the semilinear heat equation.