New results on the periodic solutions for a kind of Rayleigh equation with two deviating arguments

With the help of the continuation theorem of the coincidence degree, a priori estimates, and differential inequalities, the authors make a further investigation of a class of Rayleigh equation with two deviating arguments of the form x '' + f (x'(t)) + g(1) (t, x(t - tau(1)(t))) + g(2)(t, x(t - tau(2)(t))) = p(t). Some new results on the existence of T-periodic solutions for such a system are established. Our work generalizes and improves some earlier publications. (C) 2007 Elsevier Ltd. All rights reserved.