Oscillation theorems for second order neutral functional differential equations

摘要

Some new oscillation criteria are given for second order neutral functional differential equations of the form d2dt2( x(t) + λx [ t − τ] + μx [ t + σ]) + qx [t − α] + px [t + β] = 0, where λ, τ, μ, σ, p and q, are real numbers and α and β are real positive constants.