Acta mathematica scientia,Series A ›› 2015, Vol. 35 ›› Issue (3): 464-477.

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Dynamical Behavior of Gradient System with Small Time Delay

Yin Xunwu1, Li Desheng2   

  1. 1. School of Science, Tianjin Polytechnic University, Tianjin 300387;
    2. School of Science, Tianjin University, Tianjin 300072
  • Received:2014-05-06 Revised:2015-03-25 Online:2015-06-25 Published:2015-06-25

Abstract:

In this article, we investigate the dynamical behavior of the following general nonlinear gradient-like evolutionary equation with small time delay ∂tu+Au=f(u(t),u(t-τ)). We prove that each bounded solution of the delayed equation will converge to some equilibrium as t→∞ provided the delay is sufficiently small. This indicates that gradient system with small time delay behaves very much like the nondelayed one. The approach here is mainly based on the Morse structure of invariant sets of gradient system and some geometric analysis of evolutionary equations. The proof of this result is completed in two steps. First, with the hypothesis of gradient system, finite and isolated equilibria, we prove that there exists a sufficiently small delay such that any bounded solution of the delayed equation will ultimately enter and stay in the neighborhood of one equilibrium. Second, with the hypothesis of hyperbolic equilibrium, we utilize exponential dichotomies and a series estimates to prove that there exists ε > 0 and τ > 0 sufficiently small such that any solution of the delayed equation lying in the ε-neighborhood of one equilibrium will converge to this equilibrium as t → ∞.

Key words: Isolated hyperbolic equilibrium, Aubin-Lions lemma, Gradient system, Morse structure, Exponential dichotomies

CLC Number: 

  • O193.4
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