Published in Siberian Mathematical Journal
We describe retracts in free metabelian groups and obtain some structural results for verbally closed subgroups in free polynilpotent and free metabelian groups.
Published in Siberian Mathematical Journal
We consider a second kind representation for solutions to a first order general uniformly elliptic linear system in a simply connected plane domain \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargi...
Published in Siberian Mathematical Journal
We obtain approximation theorems for analytic functions by the shifts \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$ F(\zeta(s+i\tau)) $\end{document} with \documentcl...
Published in Siberian Mathematical Journal
The Radon transform \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$ R $\end{document} maps a function \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{was...
Published in Siberian Mathematical Journal
Suppose that \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$ n $\end{document} is an odd integer, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym...
Published in Siberian Mathematical Journal
Under consideration is the class of nonlinear systems of nonautonomous differential equations of neutral type with a variable delay that can be unbounded. Using a Lyapunov–Krasovskii functional, we establish some estimates of solutions that allow us to conclude whether the solutions are stable. In the case of exponential and asymptotic stability, w...
Published in Siberian Mathematical Journal
On the space of continuous functions from a line segment to a reflexive Banach space, we consider some operator whose values are closed convex subsets of the space. If the values are singletons, the operator becomes a well-known single-valued history-dependent operator. We study the properties of the operator, prove a fixed-point theorem analogous ...
Published in Siberian Mathematical Journal
There is a series of publications about the Riemann boundary value problem on spiral-like arcs. Some constraints are imposed on the shape of the turns which derive the latter close to approximating concentric circles in form. This article solves the problem for the spirals that may lose concentricity. We show that this effect can entail changes in ...
Published in Siberian Mathematical Journal
Considering a stationary stochastic process with independent increments (Lévy process), we study the probability of the first exit from a strip through its upper boundary. We find the two-sided inequalities for this probability under various conditions on the process.
Published in Siberian Mathematical Journal
The Gersten group \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$ G $\end{document} is the split extension \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackag...
