Boundary Value Problems
Volume 2007 (2007), Article ID 80929, 10 pages
Research Article

On Comparison Principles for Parabolic Equations with Nonlocal Boundary Conditions

Yuandi Wang1 and Hamdi Zorgati2,3

1Department of Mathematics, Shanghai University, Shanghai 200444, China
2Institut für Mathematik, Universität Zürich, Winterthurerstr. 190, Zürich CH-8057, Switzerland
3Department of Mathematics, Campus Universitaire, University of Tunis, Elmanar 2092, Tunisia

Received 5 December 2006; Revised 8 March 2007; Accepted 3 May 2007

Academic Editor: Peter Bates

Copyright © 2007 Yuandi Wang and Hamdi Zorgati. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


A generalization of the comparison principle for a semilinear and a quasilinear parabolic equations with nonlocal boundary conditions including changing sign kernels is obtained. This generalization uses a positivity result obtained here for a parabolic problem with nonlocal boundary conditions.