Electronic Journal of Differential Equations,
Vol. 2011 (2011), No. 141, pp. 1-9.

Title: Bifurcation from infinity and multiple solutions
       for first-order periodic boundary-value problems

Authors: Zhenyan Wang (Northwest Normal Univ., Lanzhou, China)
         Chenghua Gao (Northwest Normal Univ., Lanzhou, China)

Abstract:
 In this article, we study the existence and multiplicity of
 solutions for the first-order periodic boundary-value problem
 $$\displaylines{
 u'(t)-a(t)u(t)=\lambda u(t)+g(u(t))-h(t), \quad  t\in (0, T),\cr
 u(0)=u(T).
 }$$

Submitted September 6, 2011. Published October 28, 2011.
Math Subject Classifications: 34B18.
Key Words: First-order periodic problems;  Landsman-Lazer type condition; 
           Leray-Schauder degree; bifurcation; existence.