# Mathematics

## Polynomials Orthogonal with Respect to Sobolev Type Inner Product Generated by Charlier Polynomials

## The Solution of the Inverse Boundary Value Problem for a Wing Proﬁle, Located Close to Rectilinear Screen, in a New Setting

## Inverse Problem for Sturm – Liouville Operators in the Com plex Plane

## To Chang Theorem. III

## On Application of Elliptic Curves in Some Electronic Voting Protocols

Electronic voting protocols allow us to carry out voting procedure in which ballots exist only electronically. These protocols provide the secret nature of vote. The main property of electronic voting protocols is the universal checkability, i.e. provision of an opportunity to any person interested, including detached onlookers to check correctness of counting of votes at any moment. In operation cryptography protocols of electronic vote of Shauma - Pederson and Kramera - Franklin - Shoyenmeykersa - Yunga are considered.

## On the Representation of Functions by Absolutely Convergent Series by H -system

The paper deals with the representation of absolutely convergent series of functions in spaces of homogeneous type. The definition of a system of Haar type (H-system) associated to a dyadic family on a space of homogeneous type X is given in the Introduction. It is proved that for almost everywhere (a.e.) finite and measurable on a set X function f there exists an absolutely convergent series by the system H, which converges to f a.e. on X .

## Asymptotic Formulae for Weight Numbers of the Sturm–Liouville Boundary Problem on a Star-shaped Graph

In this article the Sturm-Liouville boundary value problem on the graph Γof a special structure is considered. The graph Γhas m edges, joined at one common vertex, and m vertices of degree 1. The boundary value problem is set by the Sturm-Liouville differential expression with real-valued potentials, the Dirichlet boundary conditions, and the standard matching conditions. This problem has a countable set of eigenvalues. We consider the so-called weight numbers, being the residues of the diagonal elements of the Weyl matrix in the eigenvalues.

## Stability of Periodic Billiard Trajectories in Triangle

The problem of stability of periodic billiard trajectories in triangles is considered. The notion of stability means the preservation of a period and qualitative structure of a trajectory (its combinatorial type) for sufficiently small variations of a triangle. The geometric, algebraic and fan unfoldings are introduced for stable trajectories description. The new method of fan coding, using these unfoldings, is proposed. This method permits to simplify the stability analysis.