Abubakirov, N. R. Aksentev, L. A.
Published in
Lobachevskii Journal of Mathematics

We obtain a new class of solutions to the inverse problems of the logarithmic potential in the form of a logarithmic function of a ratio of polynomials of the same degree. We give examples of finite solvability of the inverse problems.

Sokolov, E. V.
Published in
Lobachevskii Journal of Mathematics

Let G be amultiple HNN-extension of a group A, and let all its associated subgroups be properly contained in some locally nilpotent subgroup of A. We prove that if G is residually nilpotent, then all the associated subgroups are p′-isolated in A for some prime p. Moreover, if q is a prime such that G is residually a q′-torsion-free nilpotent group,...

Polyakov, A. N. Smirnova, A. N. Stepovich, M. A. Turtin, D. V.
Published in
Lobachevskii Journal of Mathematics

The qualitative properties of the two-dimensional mathematical model of excitons diffusion excited by an electron beamin a semiconductormaterial are investigated. For the studied model proved continuous dependence of the solution from the input data. It is shown that the model can be applied to estimate the diffusion coefficient and the mobility of...

Filippov, I. E. Mokeychev, V. S.
Published in
Lobachevskii Journal of Mathematics

For each ε > 0 and each scalar real valued and continuous on a compact set Ω ⊂ Rn, ξ ∈ [a, b] function g(τ, ξ) such that g(τ, a) · g(τ, b)

Sosov, E. N.
Published in
Lobachevskii Journal of Mathematics

In the present paper we obtain new metric invariants of metric spaces. These invariants can be used for classification of the finite metric spaces, their recognition and in the research of Tammes’ problem for sphere.

Vasilyev, V.
Published in
Lobachevskii Journal of Mathematics

We consider a certain class of discrete pseudo-differential operators and related equations in a sharp convex cone and describe their invertibility conditions in L2 spaces. For this purpose we introduce a concept of periodic wave factorization for elliptic symbol and show its applicability for the studying. For a half-space case we consider the Lap...

Buzyakova, R. Okunev, O.
Published in
Lobachevskii Journal of Mathematics

We study separating function sets. We find some necessary and sufficient conditions for Cp(X) or Cp2 (X) to have a point-separating subspace that is a metric space with certain nice properties. One of the corollaries to our discussion is that for a zero-dimensional X, Cp(X) has a discrete point-separating space if and only if Cp2 (X) does.

Nasyrov, S.
Published in
Lobachevskii Journal of Mathematics

We deduce a systemofODEs describing behavior of critical points and poles of a smooth one-parametric family of rational functions uniformizing a given family of ramified coverings of the Riemann sphere.

Dubey, M. K. Aggarwal, P.
Published in
Lobachevskii Journal of Mathematics

In this paper, we prove some important results of 2-absorbing ideals in a commutative ring with 1 ≠ 0. The conceptof n-weakly prime ideal in a commutative ring with 1 ≠ 0 is introduced and prove number of results concerning to n-weakly prime ideals in commutative rings.

Haydarov, F. H.
Published in
Lobachevskii Journal of Mathematics

In this paper it is given a full description of normal subgroups of index eight and ten for the group representation of a Cayley tree and counted all of them.