摘要

We mainly investigate the global boundedness of the solution to the following system, {u(t) = Delta u - chi Delta . (u del v) in Omega x R+, v(t) = Delta v - v + w in Omega x R+, w(t) = Delta w - w + u in Omega R+, under homogeneous Neumann boundary conditions with nonnegative smooth initial data in a smooth bounded domain Omega subset of R-n with critical space dimension n = 4. This problem has been considered by K. Fujie and T. Senba in [5]. They proved that for the symmetric case the condition integral(Omega) u(0) < (8 pi)(2)/chi yields global boundedness, where u(0) is the instal data for u. In this paper, inspired by some new techniques established in [3], we give a new criterion for global boundedness of the solution. As a byproduct, we obtain a simplified proof for one of the main results in [5].