Bulletin of the Malaysian Mathematical Sciences Society ( IF 1.0 ) Pub Date : 2020-07-15 , DOI: 10.1007/s40840-020-00973-0 Awatif Alqahtani , Mohamed Jleli , Mokhtar Kirane , Bessem Samet
We study the existence and nonexistence of global weak solutions to the semilinear parabolic differential inequality
$$\begin{aligned} \partial _t u-\Delta u \ge |u|^p,\quad (t,x)\in (0,\infty )\times B^c, \end{aligned}$$where \(p>1\), B is the closed unit ball in \({\mathbb {R}}^N\) (\(N\ge 2\)) and \(B^c\) is its complement, under the semilinear dynamical boundary conditions
$$\begin{aligned} \partial _t u+u \ge |u|^q +w(x), \quad (t,x)\in (0,\infty )\times \partial B \end{aligned}$$or
$$\begin{aligned} \partial _t u+\partial _\nu u +\alpha u \ge |u|^q +w(x), \quad (t,x)\in (0,\infty )\times \partial B, \end{aligned}$$where \(q>1\), \(\alpha \ge 0\), \(\partial _\nu :=\frac{\partial }{\partial \nu ^+}\), \(\nu ^+\) is the outward unit normal (relative to \(B^c\)) on \(\partial B\) and \(w\in L^1(\partial B)\), \(\int _{\partial B} w(x)\,\hbox {d}S_x\ge 0\). The cases \(\int _{\partial B} w(x)\,\hbox {d}S_x= 0\) and \(\int _{\partial B} w(x)\,\hbox {d}S_x>0\) are discussed separately.
中文翻译:
半线性动力边界条件下的外抛物型不等式
我们研究半线性抛物型微分不等式的全局弱解的存在和不存在
$$ \ begin {aligned} \ partial _t u- \ Delta u \ ge | u | ^ p,\ quad(t,x)\ in(0,\ infty)\ times B ^ c,\ end {aligned} $ $其中\(p> 1 \),B是\({\ mathbb {R}} ^ N \)(\(N \ ge 2 \))中的闭合单位球,\(B ^ c \)是其补码在半线性动力边界条件下
$$ \ begin {aligned} \ partial _t u + u \ ge | u | ^ q + w(x),\ quad(t,x)\ in(0,\ infty)\ times \ partial B \ end {aligned } $$要么
$$ \ begin {aligned} \ partial _t u + \ partial _ \ nu u + \ alpha u \ ge | u | ^ q + w(x),\ quad(t,x)\ in(0,\ infty)\ \ partial B,\ end {aligned} $$其中\(q> 1 \),\(\ alpha \ ge 0 \),\(\ partial _ \ nu:= \ frac {\ partial} {\ partial \ nu ^ +} \),\(\ nu ^ + \)是向外单位法线(相对于\(B ^ C \))上\(\局部乙\)和\(W \在L ^ 1(\部分B)\) ,\(\ INT _ { \ partial B} w(x)\,\ hbox {d} S_x \ ge 0 \)。的情况下\(\ INT _ {\部分B} W(x)的\,\ hbox中{d} S_x = 0 \)和\(\ INT _ {\部分B} W(x)的\,\ hbox中{d} S_x> 0 \)分开讨论。