An oscillation criterion for linear difference equations with oscillating coefficients

摘要

Relatively few oscillation criteria have been established for delay difference equations of the form y_(n+1) - y_n + q_ny_(n-τ) = 0, where {q_n} is an oscillatory sequence. In this note, we make use of the convexity property of the function x ln x to obtain such a criterion which complements some of the existing results even when {q_n} is nonnegative.