Threshold property of a singular stationary solution for semilinear heat equations with exponential growth

Fuente: arXiv
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Autori principali: Hisa, Kotaro, Miyamoto, Yasuhito
Natura: Preprint
Pubblicazione: 2024
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author Hisa, Kotaro
Miyamoto, Yasuhito
author_facet Hisa, Kotaro
Miyamoto, Yasuhito
contents Let $N\ge 3$. We are concerned with a Cauchy problem of the semilinear heat equation \[ \begin{cases} \partial_tu-Δu=f(u), & x\in\mathbb{R}^N,\ t>0,\\ u(x,0)=u_0(x), & x\in\mathbb{R}^N, \end{cases} \] where $f(0)=0$, $f$ is nonnegative, increasing and convex, $\log f(u)$ is convex for large $u>0$ and some additional assumptions are assumed. We establish a positive radial singular stationary solution $u^*$ such that $u^*(x)\to\infty$ as $|x|\to 0$. Then, we prove the following: The problem has a nonnegative global-in-time solution if $0\le u_0\le u^*$ and $u_0\not\equiv u^*$, while the problem has no nonnegative local-in-time solutions $u$ such that $u\ge u^*$ if $u_0\ge u^*$ and $u_0\not\equiv u^*$.
format Preprint
id arxiv_https___arxiv_org_abs_2409_16549
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Threshold property of a singular stationary solution for semilinear heat equations with exponential growth
Hisa, Kotaro
Miyamoto, Yasuhito
Analysis of PDEs
35K15, 35A01, 35A21, 35B44
Let $N\ge 3$. We are concerned with a Cauchy problem of the semilinear heat equation \[ \begin{cases} \partial_tu-Δu=f(u), & x\in\mathbb{R}^N,\ t>0,\\ u(x,0)=u_0(x), & x\in\mathbb{R}^N, \end{cases} \] where $f(0)=0$, $f$ is nonnegative, increasing and convex, $\log f(u)$ is convex for large $u>0$ and some additional assumptions are assumed. We establish a positive radial singular stationary solution $u^*$ such that $u^*(x)\to\infty$ as $|x|\to 0$. Then, we prove the following: The problem has a nonnegative global-in-time solution if $0\le u_0\le u^*$ and $u_0\not\equiv u^*$, while the problem has no nonnegative local-in-time solutions $u$ such that $u\ge u^*$ if $u_0\ge u^*$ and $u_0\not\equiv u^*$.
title Threshold property of a singular stationary solution for semilinear heat equations with exponential growth
topic Analysis of PDEs
35K15, 35A01, 35A21, 35B44
url https://arxiv.org/abs/2409.16549