Abstract and Applied Analysis 
Volume 2008 (2008), Article ID 153285, 13 pages
doi:10.1155/2008/153285
Research Article

Variational Methods for Almost Periodic Solutions of a Class of Neutral Delay Equations

M. Ayachi and J. Blot

 Laboratoire Marin Mersenne, Université Paris 1 Panthéon-Sorbonne, Centre P.M.F., 90 rue de Tolbiac, Paris Cedex 13 75634, France
Received 14 June 2007; Accepted 27 November 2007

Recommended by H. Bevan Thompson

Abstract

We provide new variational settings to study the a.p. (almost periodic) solutions of a class of nonlinear neutral delay equations. We extend Shu and Xu (2006) variational setting for periodic solutions of nonlinear neutral delay equation to the almost periodic settings. We obtain results on the structure of the set of the a.p. solutions, results of existence of a.p. solutions, results of existence of a.p. solutions, and also a density result for the forced equations.