On the decay of mass with respect to an invariant measure for semilinear heat equations in exterior domains

Fuente: arXiv
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Auteurs principaux: Fino, Ahmad, Sobajima, Motohiro
Format: Preprint
Publié: 2025
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author Fino, Ahmad
Sobajima, Motohiro
author_facet Fino, Ahmad
Sobajima, Motohiro
contents The paper concerns with the decay property of solutions to the initial-boundary value problem of the semilinear heat equation $\partial_tu-Δu+u^p=0$ in exterior domains $Ω$ in $\mathbb{R}^N$ ($N\geq 2$). The problem for the one-dimensional case is formulated with $Ω=(0,\infty)$ which is one of the representative of the connected components in $\mathbb{R}$. One can see that the $C_0$-semigroup for the corresponding linear problem possesses an invariant measure $ϕ(x)\,dx$, where $ϕ$ is a positive harmonic function satisfying the Dirichlet boundary condition. This paper clarifies that the mass of solutions with respect to the measure $ϕ(x)\,dx$ vanishes as $t\to \infty$ if and only if $1<p\leq \min\{2,1+\frac{2}{N}\}$. In the other case $p>\min\{2,1+\frac{2}{N}\}$, we prove that all solutions are asymptotically free. The asymptotic profile is actually given by a modification with Gaussian when $N\geq 3$.
format Preprint
id arxiv_https___arxiv_org_abs_2503_20480
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle On the decay of mass with respect to an invariant measure for semilinear heat equations in exterior domains
Fino, Ahmad
Sobajima, Motohiro
Analysis of PDEs
35K20, 35K58, 35B40
The paper concerns with the decay property of solutions to the initial-boundary value problem of the semilinear heat equation $\partial_tu-Δu+u^p=0$ in exterior domains $Ω$ in $\mathbb{R}^N$ ($N\geq 2$). The problem for the one-dimensional case is formulated with $Ω=(0,\infty)$ which is one of the representative of the connected components in $\mathbb{R}$. One can see that the $C_0$-semigroup for the corresponding linear problem possesses an invariant measure $ϕ(x)\,dx$, where $ϕ$ is a positive harmonic function satisfying the Dirichlet boundary condition. This paper clarifies that the mass of solutions with respect to the measure $ϕ(x)\,dx$ vanishes as $t\to \infty$ if and only if $1<p\leq \min\{2,1+\frac{2}{N}\}$. In the other case $p>\min\{2,1+\frac{2}{N}\}$, we prove that all solutions are asymptotically free. The asymptotic profile is actually given by a modification with Gaussian when $N\geq 3$.
title On the decay of mass with respect to an invariant measure for semilinear heat equations in exterior domains
topic Analysis of PDEs
35K20, 35K58, 35B40
url https://arxiv.org/abs/2503.20480