In this paper, we establish two different existence results of positive periodic solutions for
second order non-autonomous singular dynamical systems. The first one is based on a …

In this work, we study the impulsive periodic solutions of first-order singular ordinary
differential equations. The proof is based on a nonlinear alternative principle of Leray …

The existence and multiplicity of positive periodic solutions for second-order non-
autonomous singular dynamical systems are established with superlinearity or sublinearity …

We prove a Nagumo-type uniqueness result for a nonlinear differential equation on a semi-
infinite interval. A typical example of such boundary value problems is a recently derived …

In this paper, we study the existence of positive periodic solutions to second-order singular
differential equations. The proof relies on Schauder's fixed point theorem. Our results show …

In this paper, the problem of periodic solutions is studied for Liénard equations with
anindefinite singularity x′′(t)+ f (x (t)) x′(t)+ φ (t) xm (t)− α (t) x μ (t)= 0, where f:(0,+∞)→ R …

In this paper, the problem of periodic solutions is studied for second order differential
equations with indefinite singularities x ″(t)+ f (x (t)) x′(t)+ φ (t) xm (t)− α (t) x μ (t)+ β (t) xy …

We study the existence of positive periodic solutions for second order singular damped
differential equations by combining the analysis of the sign of Greenʼs functions for the …

This paper is devoted to study the existence of periodic solutions to the second-order
differential equation u''+f(u)u'+g(u)=h(t,u), where h is a Carathéodory function and f,g are …

In this paper, we study the following second‐order dynamical system: where c⩾ 0 is a
constant, and. When g admits a singularity at zero of repulsive type without the restriction of …