Acta mathematica scientia,Series A ›› 2016, Vol. 36 ›› Issue (4): 672-680.

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Life Span of Solutions for a Class of Parabolic System with Large Initial Data

Xiao Feng   

  1. School of Mathematics and Statistic, Wuhan University, Wuhan 430072
  • Received:2015-11-09 Revised:2016-04-17 Online:2016-08-26 Published:2016-08-26
  • Supported by:

    Supported by the Fundamental Research Funds for the Central Universities

Abstract:

We are concerned with the life span of solutions of the initial-boundary value problem 
utu=eav,(x,t)∈Ω×(0,T),
vtv=ebu,(x,t)∈Ω×(0,T),u(x,t)=v(x,t)=0,(x,t)∈∂Ω×(0,T),
u(x,t)=ρφ(x),v(x,t)=ρψ(x),(x,t)∈Ω×{t=0},
Here a>0, b>0 are constants, Ω is a bounded domain in RN with smooth boundary ∂Ω, ρ>0 is a parameter, and φ(x) and ψ(x) are nonnegative continuous functions on Ω. To this end, we first deduce a asymptotic lower bound on its life span by constructing a upper solution of the above initial-boundary value problem which is based on the analysis of a new ODE system, then by the comparison principle and Kaplan's method[3], we can further show that such a lower bound is indeed a asymptotic upper bound and thus we obtain the asymptotic expression of the life span of the solutions for the problem concerned.

Key words: Coupled parabolic system, Life span, Comparison principle, Kaplan's method

CLC Number: 

  • O175.4
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