2017/04/17 by Severino H. da Silva, da Silva, Severino Horácio, Antônio Luíz Pereira +1
Engineering · Mathematics · Computer Science · #Stability and Controllability of Differential Equations #Mathematical Biology Tumor Growth #Nonlinear Dynamics and Pattern Formation
paper · pdf · doi:10.48550/arxiv.1704.04938
In this paper we consider the non local evolution equation (∂ u(x,t))/(∂ t) + u(x,t)= ∫ℝNJ(x-y)f(u(y,t))ρ(y)dy+ h(x). % h ≥ 0. We show that this equation defines a continuous flow in both the space Cb(ℝN) of bounded continuous functions and the space Cρ(ℝN) of continuous functions u such that u ⋅ ρ is bounded, where ρ is a convenient "weight function"'. We show the existence of an absorbing ball for the flow in Cb(ℝN) and the existence of a global compact attractor for the flow in Cρ(ℝN), under additional conditions on the nonlinearity. We then exhibit a continuous Lyapunov function which is well defined in the whole phase space and continuous in the Cρ(ℝN) topology, allowing the characterization of the attractor as the unstable set of the equilibrium point set. We also illustrate our result with a concrete example.