Construction of a stable periodic solution to a semilinear heat equation with a prescribed profile

TL;DR

This paper constructs a stable, finite-time blow-up periodic solution for a one-dimensional semilinear heat equation with a specific blow-up profile, using finite-dimensional reduction and index theory.

Contribution

It introduces a method to explicitly construct and analyze stable blow-up solutions with prescribed profiles for semilinear heat equations.

Findings

Constructed a periodic blow-up solution with a prescribed profile.

Proved the stability of the solution with respect to initial data.

Provided a detailed description of the blow-up behavior.

Abstract

We construct a periodic solution to the semilinear heat equation with power nonlinearity, in one space dimension, which blows up in finite time $T$ only at one blow-up point. We also give a sharp description of its blow-up profile. The proof relies on the reduction of the problem to a finite dimensional one and the use of index theory to conclude. Thanks to the geometrical interpretation of the finite-dimensional parameters in terms of the blow-up time and blow-up point, we derive the stability of the constructed solution with respect to initial data.