S. R. Grace, Department of Engineering Mathematics, Faculty of Engineering,
Cairo University, Orman, Giza 12221, Egypt
e-mail: srgrace@eng.cu.edu.eg
D. O'Regan, Department of Mathematics, National University of Ireland,
Galway, Ireland
e-mail: donal.oregan@nuigalway.ie
Abstract. In this paper we shall present some new oscillation criteria for difference equations of the form
Δm x(n) + q(n) f(x[n - τ]) = 0
andΔm x(n) = q(t) f(x[n - τ]) + p(n) F(x[n + σ])
via comparison with some difference equations of lower order whose oscillatory behavior are known.2000 Mathematics Subject Classification. 39A10.
Key words and phrases. Oscillation, nonoscillation, difference, nonlinear, comparison.