Oscillations in parabolic neutral systems

Abstract

Sufficient conditions are obtained for the oscillation of all solutions of the homogeneous Neumann and Dirichlet boundary value problems associated with the neutral parabolic system \[ \frac{\partial}{\partial t} [u_i(x,t) - c_iu_i(x,t - \tau)] - D_i \nabla^2 u_i(x,t) + \sum_{j=1}^m a_{ij}u_j(x,t, - \sigma_j) = 0 \] for $i = 1, 2, ..., m; x \in \Omega \subset R^n, t \gt 0$ where $\nabla^2$ denotes the Laplacian in $R^n$.