This paper deals with a class of doubly degenerate parabolic equations, including as particular cases the porous medium equation and the degenerate pLaplace equation (p 〉 2)ut-div(b(x,t,u)|↓△u|^p-2↓△u)=f...This paper deals with a class of doubly degenerate parabolic equations, including as particular cases the porous medium equation and the degenerate pLaplace equation (p 〉 2)ut-div(b(x,t,u)|↓△u|^p-2↓△u)=f(x,u,t)The initial-boundary value problem in a bounded domain of R^N is considered under mixed boundary conditions. The existence of local-in-time weak solutions is obtained.展开更多
This paper studies the conditions of blow up in finite time of solutions of initial boundary value problem for a class nonlinear doubly degenerate parabolic equation.
This paper deals with blow-up criterion for a doubly degenerate parabolic equation of the form (u^n)t = (|ux|^m-1ux)x + u^p in (0, 1) × (0,T) subject to nonlinear boundary source (|ux|^m-1ux)(1,t...This paper deals with blow-up criterion for a doubly degenerate parabolic equation of the form (u^n)t = (|ux|^m-1ux)x + u^p in (0, 1) × (0,T) subject to nonlinear boundary source (|ux|^m-1ux)(1,t) = u^q(1,t), (|ux|^m-1ux)(0,t) = O, and positive initial data u(x,0) = uo(x), where the parameters va, n, p, q 〉0. It is proved that the problem possesses global solutions if and only if p ≤ n and q〈min {n,m(n+1)/m+1}.展开更多
In this paper, we give a complete picture of the blow-up criteria for weak solutions of the Dirichlet problem of some doubly degenerate nonlinear parabolic equations.
In this note, we study the existence of an initial trace of nonnegative solutions for the following problem ut-div(|▽um|p-2^▽um)+uq = 0 in QT = Ω × (0, T ). We prove that the initial trace is an outer r...In this note, we study the existence of an initial trace of nonnegative solutions for the following problem ut-div(|▽um|p-2^▽um)+uq = 0 in QT = Ω × (0, T ). We prove that the initial trace is an outer regular Borel measure, which may not be locally bounded for some values of parameters p, q, and m. We also study the corresponding Cauchy problems with a given generalized Borel measure as initial data.展开更多
Under some conditions, one seows that the generalized solutions of the first boundary value problem for the equation [GRAPHICS] have the property of finite speed of propagation.
The aims of this paper are to discuss the extinction and positivity for the solution of the initial boundary value problem and Cauchy problem of ut = div([↓△u^m|p-2↓△u^m). It is proved that the weak solution wi...The aims of this paper are to discuss the extinction and positivity for the solution of the initial boundary value problem and Cauchy problem of ut = div([↓△u^m|p-2↓△u^m). It is proved that the weak solution will be extinct for 1 〈 p ≤ 1 + 1/m and will be positive for p 〉 1 + 1/m for large t, where m 〉 0.展开更多
The purpose of this paper is to investigate the nonexistence of positive so lutions of the following doubly nonlinear degenerate parabolic equations:{∂u=▽k·(u^(m-1)|▽ku|^(p-2)▽ku)+(w)u^(m+p-2),u(w,0)=u0(w)≥0,...The purpose of this paper is to investigate the nonexistence of positive so lutions of the following doubly nonlinear degenerate parabolic equations:{∂u=▽k·(u^(m-1)|▽ku|^(p-2)▽ku)+(w)u^(m+p-2),u(w,0)=u0(w)≥0,u(w,t)=0,inΩ×(0,T),inΩ,on∂Ω×(0,T),where Q is a Carnot-Carathéodory metric bal in IR^(2n+1)generated by Greiner vector fields,V∈L_(loc)(Ω),k∈N,m∈R,1<p<2n+2k and m+p-2>0.The better lower bound p*for m+p is found and the nonexistence results are proved for p*≤m+p<3.展开更多
基金The NSFC(10371050)and the"985"program of Jilin University.
文摘This paper deals with a class of doubly degenerate parabolic equations, including as particular cases the porous medium equation and the degenerate pLaplace equation (p 〉 2)ut-div(b(x,t,u)|↓△u|^p-2↓△u)=f(x,u,t)The initial-boundary value problem in a bounded domain of R^N is considered under mixed boundary conditions. The existence of local-in-time weak solutions is obtained.
文摘This paper studies the conditions of blow up in finite time of solutions of initial boundary value problem for a class nonlinear doubly degenerate parabolic equation.
文摘This paper deals with blow-up criterion for a doubly degenerate parabolic equation of the form (u^n)t = (|ux|^m-1ux)x + u^p in (0, 1) × (0,T) subject to nonlinear boundary source (|ux|^m-1ux)(1,t) = u^q(1,t), (|ux|^m-1ux)(0,t) = O, and positive initial data u(x,0) = uo(x), where the parameters va, n, p, q 〉0. It is proved that the problem possesses global solutions if and only if p ≤ n and q〈min {n,m(n+1)/m+1}.
基金the Natural Science Foundation of Fujian Province of China (No.Z0511048)
文摘In this paper, we give a complete picture of the blow-up criteria for weak solutions of the Dirichlet problem of some doubly degenerate nonlinear parabolic equations.
文摘In this note, we study the existence of an initial trace of nonnegative solutions for the following problem ut-div(|▽um|p-2^▽um)+uq = 0 in QT = Ω × (0, T ). We prove that the initial trace is an outer regular Borel measure, which may not be locally bounded for some values of parameters p, q, and m. We also study the corresponding Cauchy problems with a given generalized Borel measure as initial data.
文摘Under some conditions, one seows that the generalized solutions of the first boundary value problem for the equation [GRAPHICS] have the property of finite speed of propagation.
基金The project is supported by NSFC(10371050,10571072)by the 985 program of Jilin University
文摘The aims of this paper are to discuss the extinction and positivity for the solution of the initial boundary value problem and Cauchy problem of ut = div([↓△u^m|p-2↓△u^m). It is proved that the weak solution will be extinct for 1 〈 p ≤ 1 + 1/m and will be positive for p 〉 1 + 1/m for large t, where m 〉 0.
基金support from Nature Science Fund of China(No.11771354).
文摘The purpose of this paper is to investigate the nonexistence of positive so lutions of the following doubly nonlinear degenerate parabolic equations:{∂u=▽k·(u^(m-1)|▽ku|^(p-2)▽ku)+(w)u^(m+p-2),u(w,0)=u0(w)≥0,u(w,t)=0,inΩ×(0,T),inΩ,on∂Ω×(0,T),where Q is a Carnot-Carathéodory metric bal in IR^(2n+1)generated by Greiner vector fields,V∈L_(loc)(Ω),k∈N,m∈R,1<p<2n+2k and m+p-2>0.The better lower bound p*for m+p is found and the nonexistence results are proved for p*≤m+p<3.