{"title":"一类非齐次抛物型方程的适定性和爆破","authors":"M. Majdoub","doi":"10.7153/DEA-2021-13-06","DOIUrl":null,"url":null,"abstract":"We consider the large-time behavior of sign-changing solutions of the inhomogeneous equation $u_t-\\Delta u=|x|^\\alpha |u|^{p}+\\zeta(t)\\,{\\mathbf w}(x)$ in $(0,\\infty)\\times{\\mathbb{R}}^N$, where $N\\geq 3$, $p>1$, $\\alpha>-2$, $\\zeta, {\\mathbf w}$ are continuous functions such that $\\zeta(t)\\sim t^\\sigma$ as $t\\to 0$, $\\zeta(t)\\sim t^m$ as $t\\to\\infty$ . We obtain local existence for $\\sigma>-1$. We also show the following: \n$-$ If $m\\leq 0$, $p 0$, then all solutions blow up in finite time; \n$-$ If $m> 0$, $p>1$ and $\\int_{\\mathbb{R}^N}{\\mathbf w}(x)dx>0$, then all solutions blow up in finite time. \nThe main novelty in this paper is that blow up depends on the behavior of $\\zeta$ at infinity.","PeriodicalId":51863,"journal":{"name":"Differential Equations & Applications","volume":" ","pages":""},"PeriodicalIF":0.7000,"publicationDate":"2020-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"5","resultStr":"{\"title\":\"Well-posedness and blow-up for an inhomogeneous semilinear parabolic equation\",\"authors\":\"M. Majdoub\",\"doi\":\"10.7153/DEA-2021-13-06\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"We consider the large-time behavior of sign-changing solutions of the inhomogeneous equation $u_t-\\\\Delta u=|x|^\\\\alpha |u|^{p}+\\\\zeta(t)\\\\,{\\\\mathbf w}(x)$ in $(0,\\\\infty)\\\\times{\\\\mathbb{R}}^N$, where $N\\\\geq 3$, $p>1$, $\\\\alpha>-2$, $\\\\zeta, {\\\\mathbf w}$ are continuous functions such that $\\\\zeta(t)\\\\sim t^\\\\sigma$ as $t\\\\to 0$, $\\\\zeta(t)\\\\sim t^m$ as $t\\\\to\\\\infty$ . We obtain local existence for $\\\\sigma>-1$. We also show the following: \\n$-$ If $m\\\\leq 0$, $p 0$, then all solutions blow up in finite time; \\n$-$ If $m> 0$, $p>1$ and $\\\\int_{\\\\mathbb{R}^N}{\\\\mathbf w}(x)dx>0$, then all solutions blow up in finite time. \\nThe main novelty in this paper is that blow up depends on the behavior of $\\\\zeta$ at infinity.\",\"PeriodicalId\":51863,\"journal\":{\"name\":\"Differential Equations & Applications\",\"volume\":\" \",\"pages\":\"\"},\"PeriodicalIF\":0.7000,\"publicationDate\":\"2020-08-04\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"5\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Differential Equations & Applications\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.7153/DEA-2021-13-06\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"MATHEMATICS, APPLIED\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Differential Equations & Applications","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.7153/DEA-2021-13-06","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATHEMATICS, APPLIED","Score":null,"Total":0}
Well-posedness and blow-up for an inhomogeneous semilinear parabolic equation
We consider the large-time behavior of sign-changing solutions of the inhomogeneous equation $u_t-\Delta u=|x|^\alpha |u|^{p}+\zeta(t)\,{\mathbf w}(x)$ in $(0,\infty)\times{\mathbb{R}}^N$, where $N\geq 3$, $p>1$, $\alpha>-2$, $\zeta, {\mathbf w}$ are continuous functions such that $\zeta(t)\sim t^\sigma$ as $t\to 0$, $\zeta(t)\sim t^m$ as $t\to\infty$ . We obtain local existence for $\sigma>-1$. We also show the following:
$-$ If $m\leq 0$, $p 0$, then all solutions blow up in finite time;
$-$ If $m> 0$, $p>1$ and $\int_{\mathbb{R}^N}{\mathbf w}(x)dx>0$, then all solutions blow up in finite time.
The main novelty in this paper is that blow up depends on the behavior of $\zeta$ at infinity.