The large contraction principle and existence of periodic solutions for infinite delay Volterra difference equations

In this article, we establish sufficient conditions for the existence of periodic solutions of a nonlinear infinite delay Volterra difference equation: Delta x(n) = p(n) + b(n)h(x(n)) + Sigma(n)(k=-infinity) B (n, k)g(x(k)). We employ a Krasnosel'skii type fixed point theorem, originally proved by Burton. The primary sufficient condition is not verifiable in terms of the parameters of the difference equation, and so we provide three applications in which the primary sufficient condition is verified.