Fisher–KPP equation on the Heisenberg group

In this paper, we consider the Fisher–KPP equation on the Heisenberg group. We discuss the existence of global solutions, asymptotic behavior of global solutions and blow-up solutions. Moreover, we extend the obtained results to the time-fractional Fisher–KPP equation on the Heisenberg group.     

Existence of L 1-Connections Between Equilibria of a Semilinear Parabolic Equation

We give a necessary and sufficient condition for the existence of L ¹-connections between equilibria of a semilinear parabolic equation. By an L ¹-connection from an equilibrium ^– to an equilibrium ⁺ we mean a function u(, t) which is a classical solution on the interval (–, T) for some T and blows up at t = T but continues to exist in the space L ¹ for t [T, ) and satisfies u(, t) ^± (in a suitable sense) as t ±. The main tool in our analysis is the zero number.     

BLOW－UP AND DIE－OUT OF SOLUTIONS OF NONLINEAR PSEUDO-HYPERBOLIC EQUATIONS OF GENERALIZED NERVE CONDUCTION TYPE

ＢＬＯＷ－ＵＰＡＮＤＤＩＥ－ＯＵＴＯＦＳＯＬＵＴＩＯＮＳＯＦＮＯＮＬＩＮＥＡＲＰＳＥＵＤＯＨＹＰＥＲＢＯＬＩＣＥＱＵＡＴＩＯＮＳＯＦＧＥＮＥＲＡＬＩＺＥＤＮＥＲＶＥＣＯＮＤＵＣＴＩＯＮＴＹＰＥＷａｎｇＦａｎｂｉｎ（王凡彬）（ＲｅｃｅｉｖｅｄＪｕｎｅ２...     

On divisorial filtrations on sheaves

In this paper, we generalize the notion of Poincaré series of a multi-index divisorial filtration corresponding to a collection of sigma-processes to the case of an arbitrary locally-free sheaf on the space of blow-ups of the complex plane ?². For an arbitrary sheaf, we establish a representation of the series in terms of topological invariants of the sheaf. In particular, for the sheaf of functions, this representation coincides with the Poincaré series obtained by Gusein—Zade and Delgado.     

A lower bound for the blow-up time to a damped semilinear wave equation

This paper studies the blow-up property of weak solutions to an initial and boundary value problem for a nonlinear viscoelastic hyperbolic equation with nonlinear sources. A lower bound for the blow-up time is given.     

Uniform Blow-up Behavior for Degenerate and Singular Parab olic Equations

This paper deals with the degenerate and singular parabolic equations coupled via nonlinear nonlocal reactions, subject to zero-Dirichlet boundary conditions. After giving the existence and uniqueness of local classical nonnegative solutions, we show critical blow-up exponents for the solutions of the system. Moreover, uniform blow-up behaviors near the blow-up time are obtained for simultaneous blow-up solutions, divided into four subcases.     

含梯度项的椭圆方程组的边界爆破解

研究了含梯度项的椭圆方程组的边界爆破解的性质,其中权函数a(x),b(x)为正并且满足一定的条件.利用上下解的方法及比较原则证明了正解的存在性与唯一性,并得到了边界爆破速率的估计.     

Blow-up and propagation of disturbances for fast diffusion equations

This paper is concerned with the Cauchy problem for the fast diffusion equation _ut−Δu^m=αu^_p1$u_t-\Delta u^m=\alpha u^{p_1}$ in R^N${\mathbb{R}}^N$ (N≥1$N\ge 1$), where m∈(0,1)$m\in (0,1)$, _p1>1$p_1>1$ and α>0$\alpha >0$. The initial condition _u0$u_0$ is assumed to be continuous, nonnegative and bounded. Using a technique of subsolutions, we set up sufficient conditions on the initial value _u0$u_0$ so that u(t,x)$u(t,x)$ blows up in finite time, and we show how to get estimates on the profile of u(t,x)$u(t,x)$ for small enough values of t>0$t>0$.