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New Kamenev-type oscillation criteria for second order neutral nonlinear differential equations. (English) Zbl 1142.34360
Six theorems are proved, which establish some new Kamenev-type oscillation criteria for second order neutral delay nonlinear differential equations. In view of the fact that the authors study the problem by using a new technique, the proved results are different in some sense from the most known ones. In the paper a new class of functions is defined. The existence of a function from this class which satisfies some integral conditions, guarantees that the equation is oscillatory. The established criteria in some sense are sharper than previous results obtained by other authors.
MSC:
 34K11 Oscillation theory of functional-differential equations 34K40 Neutral functional-differential equations
neutral type