# On property (B) of higher order delay differential equations

## Blanka Baculíková and Jozef Džurina

Address: Department of Mathematics, Faculty of Electrical Engineering and Informatics, Technical University of Košice, Letná 9, 042 00 Košice, Slovakia

E-mail:

blanka.baculikova@tuke.sk

jozef.dzurina@tuke.sk

Abstract: In this paper we offer criteria for property (B) and additional asymptotic behavior of solutions of the $n$-th order delay differential equations
\begin{equation*} \big (r(t)\big [x^{(n-1)}(t)\big ]^{\gamma }\big )^{\prime }=q(t)f\big (x(\tau (t))\big )\,. \end{equation*}
Obtained results essentially use new comparison theorems, that permit to reduce the problem of the oscillation of the n-th order equation to the the oscillation of a set of certain the first order equations. So that established comparison principles essentially simplify the examination of studied equations. Both cases $\int ^{\infty } r^{-1/\gamma }(t)\,{t}=\infty $ and $\int ^{\infty } r^{-1/\gamma }(t)\,{t}<\infty $ are discussed.

AMSclassification: primary 34K11; secondary 34C10.

Keywords: n-th order differential equations, comparison theorem, oscillation, property (B).

DOI: 10.5817/AM2012-4-301