Boundary Value Problems
Volume 2008 (2008), Article ID 197205, 21 pages
Research Article

Multiplicity Results via Topological Degree for Impulsive Boundary Value Problems under Non-Well-Ordered Upper and Lower Solution Conditions

Xu Xian,1 Donal O'Regan,2 and R. P. Agarwal3

1Department of Mathematics, Xuzhou Normal University, Xuzhou, Jiangsu 221116, China
2Department of Mathematics, National University of Ireland, Galway, Ireland
3Department of Mathematical Science, Florida Institute of Technology, Melbourne, FL 32901, USA

Received 14 April 2008; Accepted 26 August 2008

Academic Editor: R. P. Gilbert

Copyright © 2008 Xu Xian et al. 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.


Some multiplicity results for solutions of an impulsive boundary value problem are obtained under the condition of non-well-ordered upper and lower solutions. The main ideas of this paper are to associate a Leray-Schauder degree with the lower or upper solution.