arXiv subjects
Publications and source records attributed to Evgeny Sevost'yanov.
We study the factor-spaces of the unit ball of dimension, not less than three, by a certain group of Möbius transformations. For mappings of such spaces, an estimate of the distortion of the modulus of families of spheres is obtained. As applications, we obtain theorems on the locally and boundary behavior of the Orlicz--Sobolev classes between factor spaces.
In this article, we study mappings acting between domains of two factor spaces by certain groups of Möbius automorphisms of the unit ball that act discontinuously and do not have fixed points. For such mappings, we have established estimates for the distortion of the modulus of families of paths, which are similar to the well-known Poletsky and Väisälä inequalities. As applications, we have obtained several important results on the local and boundary behavior of mappings.
We have found one of the possible conditions under which the Beltrami equation with degeneration of ellipticity has a continuous solution of the Sobolev class. With some additional requirements, this solution is homeomorphic
The article is devoted to the study of mappings with finite distortion in metric spaces. Analogues of results relating to equicontinuity and normality of families of quasiregular mappings are obtained. It is proved that the indicated families are equicontinuous if the characteristic of the mappings has a finite mean oscillation at each inner point, and the maps omit a certain fixed continuum. An equicontinuity of generalized quasiisometries on Riemannian manifolds is also obtained.
We consider a class of so-called ring $Q$-mappings that are a generalization of quasiconformal mappings. Theorems on the local behavior of inverse maps of this class are obtained. Under certain conditions, we also investigated the behavior of families of these mappings in the closure of the domain
In the present paper, homeomorphisms in metric spaces which generalize quasiconformal mappings, are investigated. It is proved that, at some conditions on metric spaces and boundaries of corresponding domains, families of above mappings are equicontinuous in a closure of a given domain.
A boundary behavior of mappings, which are closely related with Sobolev and Orlicz--Sobolev classes in the plane and in the space, is investigated. There are obtained theorems on boundary behavior of classes mentioned above.
A behavior of homeomorphisms of Orlicz--Sobolev classes in a closure of a domain is investigated. There are obtained theorems about equicontinuity of classes mentioned above in terms of prime ends of regular domains. In particular, it is proved that above classes are equicontinuous in domains with some restrictions on it's boundaries provided that the corresponding inner dilatation of order $p$ has a majorant of finite mean oscillation at every point.
A class of space mappings of finite distortion with $N$ and $N^{\,-1}$ Luzin properties with respect to $k$-measured area is investigated. It is proved that, mappings mentioned above satisfy upper and lower inequalities for families of $k$-measures surfaces.
A boundary behavior of closed open discrete mappings of Sobolev and Orlicz--Sobolev classes in ${\Bbb R}^n,$ $n\ge 3,$ is studied. It is proved that, mappings mentioned above have a continuous extension to boundary point $x_0$ of a domain $D$ whenever its inner dilatation of order $p$ has a majorant $FMO$ (finite mean oscillation) at the point. Another sufficient condition of possibility of continuous extension is a divergence of some integral.
In the present paper, questions about a local behavior of mappings $f:D\rightarrow \overline{{\Bbb R}^n},$ $n\ge 2,$ in $\overline{D}$ are studied. Under some conditions on a measurable function $Q(x),$ $Q:D\rightarrow [0, \infty],$ and boundaries of $D$ and $D^{\,\prime}=f(D),$ it is showed that a family of open discrete map\-ping $f:D\rightarrow \overline{{\Bbb R}^n},$ $n\ge 2,$ with characteristic of quasiconformality $Q(x),$ is equicontinuous in $\overline{D}.$
Open discrete mappings with a modulus condition in metric spaces are considered. Some results related to local behavior of mappings as well as theorems about continuous extension to a boundary are proved.
A paper is devoted to study of one class of space mappings which are more general than mappings with bounded distortion. It is showed that a locally uniformly limit of a sequence of mappings $f:D\rightarrow {\Bbb R}^n$ of domain $D\subset{\Bbb R}^n,$ $n\geqslant 2,$ satisfying one inequality with respect to $p$-modulus of families of curves, is light. The above statement is a generalization of well-known theorem about openness and discreteness of uniformly limit of a sequence of mappings with bounded distortion.
For mappings in metric spaces satisfying one inequality with respect to modulus of families of curves, there is proved a lightness of preimage under the mapping. It is proved that, the mappings, satisfying estimate mentioned above, are light, whenever a function which corresponds to distortion of families of curves under the mapping, is of finite mean oscillation at every point.
We prove that open discrete mappings of Sobolev classes $W_{\rm loc}^{1, p},$ $p>n-1,$ with locally integrable inner dilatations admit $ACP_p^{\,-1}$-property, which means that these mappings are absolutely continuous on almost all preimage paths with respect to $p$-module. In particular, our results extend the well-known Poletski\uı lemma for quasiregular mappings. We also establish the upper bounds for $p$-module of such mappings in terms of integrals depending on the inner dilatations and arbitrary admissible functions.
Theorems on continuous extension on boundary for one class of open discrete mappings between Riemannian manifolds are obtained. In particular, there is proved that, open discrete ring $Q$-mappings $f:D\rightarrow D^{\,\prime}$ are extend to $\partial D$ whenever $\partial D$ is locally connected, $\partial D^{\,\prime}$ is strongly accessible, and a function $Q$ has finite mean oscillation at $\partial D.$
A paper is devoted to study of local behavior of so-called $Q$-mappings including qua\-si\-con\-for\-mal mappings and mappings with bounded distortion. It is showed that, such mappings have removable isolated singularities whenever the grow of the mappings is note more than some function of a radius of a ball.
A paper is devoted to study of topological properties of some class of space mappings. It is showed that, sense preserving mappings $f:D\rightarrow \overline{{\Bbb R}^n}$ of a domain $D\subset{\Bbb R}^n,$ $n\geqslant 2,$ satisfying some modulus inequality with respect to $p$-modulus of families of curves, are open and discrete at some restrictions on a function $Q,$ which determinate inequality mentioned above.