Positive Solutions and Oscillation

Agacik Zafer, Yasemin Yalcin and Yeter S.Yilmaz

Address. Department of Mathematics, Middle East Technical University, 06531 Ankara, Turkey
                Department of Mathematics, Middle East Technical University, 06531 Ankara, Turkey
                Department of Mathematics, Atilim University, 06830 Ankara, Turkey

E-mail: zafer@math.metu.edu.tr
             yaseminy@metu.edu.tr

Abstract. Sufficient conditions are established for the existence of positive solutions and oscillation of bounded solutions of $p$-th order neutral difference equations of the form $$ \Delta^p[x_n+a_nx_{\tau(n)}]+\delta\, q_nf(x_{\sigma(n)}) = h_n, \quad n\in \N(n_0), $$ where $\delta = \pm 1$, $\N(n_0)=\{n_0,n_0+1,\ldots \}$, $n_0$ is fixed in $\N=\{1,2,\ldots\}$, $a, q, h:\;\N(n_0)\rightarrow \R,$ $\tau,\sigma\in \N(n_0)\rightarrow \N$ with $\tau(n)

AMSclassification. 39A10, 34A11, 34A99

Keywords. Higher order neutral equations, positive solution, oscillation