scholarly journals Noncanonical Neutral DDEs of Second-Order: New Sufficient Conditions for Oscillation

Mathematics ◽  
2021 ◽  
Vol 9 (17) ◽  
pp. 2026
Author(s):  
Awatif A. Hindi ◽  
Osama Moaaz ◽  
Clemente Cesarano ◽  
Wedad R. Alharbi ◽  
Mohamed A. Abdou

In this paper, new oscillation conditions for the 2nd-order noncanonical neutral differential equation (a0t((ut+a1tug0t)′)β)′+a2tuβg1t=0, where t≥t0, are established. Using Riccati substitution and comparison with an equation of the first-order, we obtain criteria that ensure the oscillation of the studied equation. Furthermore, we complement and improve the previous results in the literature.

2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
Osama Moaaz

AbstractThe aim of this work is to offer sufficient conditions for the oscillation of neutral differential equation second order $$ \bigl( r ( t ) \bigl[ \bigl( y ( t ) +p ( t ) y \bigl( \tau ( t ) \bigr) \bigr) ^{\prime } \bigr] ^{\gamma } \bigr) ^{\prime }+f \bigl( t,y \bigl( \sigma ( t ) \bigr) \bigr) =0, $$(r(t)[(y(t)+p(t)y(τ(t)))′]γ)′+f(t,y(σ(t)))=0, where $\int ^{\infty }r^{-1/\gamma } ( s ) \,\mathrm{d}s= \infty $∫∞r−1/γ(s)ds=∞. Based on the comparison with first order delay equations and by employ the Riccati substitution technique, we improve and complement a number of well-known results. Some examples are provided to show the importance of these results.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Ercan Tunç ◽  
Said R. Grace

This paper discusses oscillatory and asymptotic properties of solutions of a class of second-order nonlinear damped neutral differential equations. Some new sufficient conditions for any solution of the equation to be oscillatory or to converge to zero are given. The results obtained extend and improve some of the related results reported in the literature. The results are illustrated with examples.


1991 ◽  
Vol 43 (1) ◽  
pp. 147-152 ◽  
Author(s):  
Shigui Ruan

In this paper, sufficient conditions for oscillations of the first order neutral differential equation with variable coefficientsare obtained, where c, τ, σ and µ are positive constants, p, q ∈ C ([t0, ∞), R+).


2017 ◽  
Vol 8 (3) ◽  
Author(s):  
Srinivasan Selvarangam ◽  
Bose Rani ◽  
Ethiraju Thandapani

AbstractIn this paper, some new sufficient conditions are established for the oscillation of all solutions of the second-order neutral differential equation with mixed neutral terms of the formfor all


1995 ◽  
Vol 8 (1) ◽  
pp. 77-83 ◽  
Author(s):  
S. C. Palaniswami

The existence of positive solutions of second order neutral differential equation of the form [x(t)−cx(t−h)]′​′+∑i=1mpi(t)x[gi(t)]=0, t≥t0,                                          (A) is investigated. Some sufficient conditions are given for the existence of positive solutions with asymptotic decay of (A). Examples are presented to illustrate the results.


1989 ◽  
Vol 39 (1) ◽  
pp. 71-80 ◽  
Author(s):  
L.H. Erbe ◽  
B.G. Zhang

Some new sufficient conditions are obtained for the oscillation of the neutral differential equationwhere r(t) > 0, 0 < c < 1, p(t) ≥ 0, σ(t) > τ > 0 and α = 1 or 0 < α < 1.


Philosophia ◽  
2021 ◽  
Author(s):  
Ricardo Parellada

AbstractThe relation between conceptual analysis and empirical observations when ascribing or denying concepts and beliefs to non-human animals is not straightforward. In order to reflect on this relation, I focus on two theoretical proposals (Davidson’s and Allen’s) and one empirical case (vervet monkeys’ alarm calls), the three of which are permanently discussed and considered in the literature on animal cognition. First, I review briefly Davidson’s arguments for denying thought to non-linguistic animals. Second, I review Allen’s criteria for ascribing concepts to creatures capable of correcting their discriminatory powers by taking into account their previous errors. Allen affirms that this is an empirical proposal which offers good reasons, but not necessary or sufficient conditions, for concept attribution. Against Allen, I argue that his important proposal is not an empirical, but a conceptual one. Third, I resort to vervet monkeys to show that Allen’s criteria, and not Davidson’s, are very relevant for ascribing first-order and denying second-order beliefs to this species and thus make sense of the idea of animal cognition.


1992 ◽  
Vol 15 (3) ◽  
pp. 509-515 ◽  
Author(s):  
B. S. Lalli ◽  
B. G. Zhang

An existence criterion for nonoscillatory solution for an odd order neutral differential equation is provided. Some sufficient conditions are also given for the oscillation of solutions of somenth order equations with nonlinearity in the neutral term.


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