主 题: Unbounded Positive Solutions of Some Nonlinear Stochastic Parabolic Equations 
报告人: Prof. Pao-Liu Chow (Department of Mathematics, Wayne State University, USA)
时 间: 2012-10-17 16:00-17:00
地 点: 理科一号楼1479 
  
 The talk is concerned with unbounded solutions of some semi-linear parabolic equations 
  
 perturbed by a multiplicative Gaussian white-noise random field. Such equations 
  
 arise, for example, from turbulent diffusion and population dynamics in a random 
  
 environment. In particular we are mainly interested in the possible existence of 
  
 a positive explosive solution, that is, it will become unbounded in finite time in some 
  
 sense. To this end we first prove that, under some suitable conditions, a stochastic 
  
 parabolic equation can have a positive solution. Next, without the positivity 
  
 conditions, we shall provide a set of sufficient conditions for explosion with positive 
  
 probability based on the Lyapunov function type of technique. In the case of positive 
  
 solutions, it is possible to obtain more explicit conditions for explosion. Assume that 
  
 the positivity condtions hold and the nonlinear term is convex, among some other 
  
 auxiliary conditions. It will be shown that there exists a positive solution which will 
  
 explode either with positive probability or in the mean