二阶变时滞非线性差分方程的振动性

建立了二阶变时滞非线性差分方程△ (pn(△yn) σ) +qnf(yn-kn) =0的一些新的振动性定理 ,其中△yn=yn+ 1-yn 是差分算子 ,{kn}是非负整数序列 ,{n-kn}单调不减 ,σ是两个正奇数之商 ,{qn}是非负实数序列 ,{pn}是正实数序列 ,f是 (-∞ ,+∞ )上的连续函数

Oscillation of Second Order Variable Nonlinear Difference Equations

We establish some new oscillation criteria for the second variable delay nonlinear difference equations △(p n(△y n) σ)+q nf(y n-k n )=0,where △y n=y n+1 -y n is a difference operator,｛k n｝ is a sequence of positive integrals,the sequence ｛n-k n｝ is non decreasing,σ is a quotient of positive odd integrals,｛q n｝ is a sequence of nonegative real numbers,｛p n｝ is a sequence of positive real numbers,f is continuous on (-∞,+∞)