We study relations between the almost specification property, the asymptotic average shadowing property and the average shadowing property for dynamical systems on compact metric spaces. We show implications between these properties and relate them to other important notions such as shadowing, transitivity, invariant measures, etc. We provide examples showing that compactness is a necessary condition for these implications to hold. As a consequence, we also obtain a proof that limit shadowing in...

The author considers the quasilinear differential equations $$\begin{array}{c}{\left(r\left(t\right)\varphi \left(x^{\text{'}}\right)\right)}^{\text{'}}+q\left(t\right)f\left(x\right)=0,t\ge a\\ \multicolumn{2}{c}{\text{and}}\\ {\left(r\left(t\right)\varphi \left(x^{\text{'}}\right)\right)}^{\text{'}}+F(t,x)=\pm g\left(t\right),t\ge a.\end{array}$$ By means of topological tools there are established conditions ensuring the existence of nonnegative asymptotic decaying solutions of these equations.

The paper describes asymptotic properties of a strongly nonlinear system $\dot{x}=f(t,x)$, $(t,x)\in ℝ\times {ℝ}^n$. The existence of an $\lfloor n/2\rfloor$ parametric family of solutions tending to zero is proved. Conditions posed on the system try to be independent of its linear approximation.

We investigate an asymptotic behaviour of damped non-oscillatory solutions of the initial value problem with a time singularity ${\left(p\left(t\right)u^{\text{'}}\left(t\right)\right)}^{\text{'}}+p\left(t\right)f\left(u\left(t\right)\right)=0$, $u\left(0\right)=u_0$, $u^{\text{'}}\left(0\right)=0$ on the unbounded domain $[0,\infty )$. Function $f$ is locally Lipschitz continuous on $ℝ$ and has at least three zeros $L_0<0$, $0$ and $L>0$. The initial value $u_0\in (L_0,L)\setminus \left\{0\right\}$. Function $p$ is continuous on $[0,\infty ),$ has a positive continuous derivative on $(0,\infty )$ and $p\left(0\right)=0$. Asymptotic formulas for damped non-oscillatory solutions and their first derivatives are derived under some additional assumptions. Further, we provide...

The paper deals with existence of Kneser solutions of $n$-th order nonlinear differential equations with quasi-derivatives.

The paper deals with oscillation criteria of fourth order linear differential equations with quasi-derivatives.

The paper deals with the oscillation of a differential equation $L_{4}y+P\left(t\right)L_{2}y+Q\left(t\right)y\equiv 0$ as well as with the structure of its fundamental system of solutions.