Open Access Open Access  Restricted Access Access granted  Restricted Access Subscription Access

Vol 37, No 2 (2016)

Article

Sum-difference equation for analytic functions generated by pentagon and its application

Aksenteva E.P., Garifyanov F.N.

Abstract

For analytic functions, we study poly-element linear functional equation generated by a pentagon. Such equations are connected with the moment problem for entire functions of exponential type.

Lobachevskii Journal of Mathematics. 2016;37(2):101-104
pages 101-104 views

Solution of nonlinear fractional stochastic integro-differential equation

Ahmed H.M.

Abstract

By using admissibility theory and fixed point theorems, we studied the existence and uniqueness of random solution of nonlinear fractional stochastic integro-differential equation of Volterra type. In the end, an example is given to show the application of our results.

Lobachevskii Journal of Mathematics. 2016;37(2):105-113
pages 105-113 views

An analog of Titchmarsh’s theorem for the generalized Fourier–Bessel Transform

Daher R., El hamma M., El ouadih S.

Abstract

Using a generalized translation operator, we obtain an analog of Titchmarsh’s theorem for the generalized Fourier–Bessel transform for functions satisfying the 2n-Bessel–Lipschitz condition in the space Lα,n2.

Lobachevskii Journal of Mathematics. 2016;37(2):114-119
pages 114-119 views

On existence of solutions for fractional differential equations with nonlocal multi-point boundary conditions

Houas M., Dahmani Z.

Abstract

This paper investigates the existence of solutions for a boundary value problem of nonlinear fractional differential equations with nonlocal boundary conditions. We use Banach fixed point theorem to prove an existence and uniqueness result. Then, by using O’Regan fixed point theorem, we prove an existence result. Finally, illustrative examples of our main results are presented.

Lobachevskii Journal of Mathematics. 2016;37(2):120-127
pages 120-127 views

An algorithm for counting smooth integers

Ishmukhametov S., Sharifullina F.

Abstract

An integer number n > 0 is called y-smooth for y > 0 if any prime factor p of n satisfies py. Let ψ(x, y) be the number of all y-smooth integers less or equal to x. In this paper we elaborate a new algorithm for approximate calculation of ψ(x, y) at large x and relatively small y < log x.

Lobachevskii Journal of Mathematics. 2016;37(2):128-137
pages 128-137 views

A functional central limit theorem for Hilbert-valued martingales

Lavrentyev V.V., Nazarov L.V.

Abstract

Weak convergence of martingales with values in Hilbert space is studied in the paper. Necessary and sufficient conditions for the convergence to Gaussian martingale with continuous trajectories are obtained.

Lobachevskii Journal of Mathematics. 2016;37(2):138-145
pages 138-145 views

Para-Sasakian manifolds satisfying certain curvature conditions

Mandal K., De U.C.

Abstract

In this paper, we investigate P-Sasakian manifolds satisfying the conditions R(X, ξ) · C = 0 and \(C \cdot \widetilde Z = 0\), where C and \(\widetilde Z\) are the Weyl conformal curvature tensor and the concircular curvature tensor respectively. Next, we study 3-dimensional P-Sasakianmanifolds. Finally, we give an example of a 3-dimensional P-Sasakian manifold.

Lobachevskii Journal of Mathematics. 2016;37(2):146-154
pages 146-154 views

On an inequality of Paul Turan concerning polynomials

Mir A., Dewan K.K., Hussain I.

Abstract

Let P(z) be a polynomial of degree n and Ps(z) be its sth derivative. In this paper, we shall prove some inequalities for the sth derivative of a polynomial having zeros inside a circle, which as a special case give generalizations and refinements of some results of Turan, Govil, Malik and others.

Lobachevskii Journal of Mathematics. 2016;37(2):155-159
pages 155-159 views

Normal connections on three-dimensional manifolds with solvable transformation group

Mozhey N.

Abstract

The purpose of the work is the classification of three-dimensional homogeneous spaces, allowing a normal connection, description of invariant affine connections on those spaces together with their curvature and torsion tensors, holonomy algebras. We consider only the case, when Lie group is solvable. The local classification of homogeneous spaces is equivalent to the description of the effective pairs of Lie algebras. We study the holonomy algebras of homogeneous spaces and find when the invariant connection is normal. Studies are based on the use of properties of the Lie algebras, Lie groups and homogeneous spaces and they mainly have local character.

Lobachevskii Journal of Mathematics. 2016;37(2):160-176
pages 160-176 views

Some properties of three dimensional trans-Sasakian manifolds with a semi-symmetric metric connection

Pahan A.S., Bhattacharyya B.A.

Abstract

In this paper we have studied ξ-projectively flat 3-dimensional trans-Sasakian manifold with respect to semi-symmetric metric connection. Next, we have shown a skew-symmetric property of projective Ricci-tensor with respect to semi-symmetric metric connection in a 3-dimensional trans-Sasakian manifold. Then we have proved quasi-projectively flat, ϕ-projectively flat 3-dimensional trans-Sasakian manifold with semi-symmetric metric connection. In the last section we have shown an example of a three dimensional trans-Sasakian manifold with respect to semi-symmetric metric connection.

Lobachevskii Journal of Mathematics. 2016;37(2):177-184
pages 177-184 views

Non-existence of harmonic maps on trans-Sasakian manifolds

Jaiswal A.J., Pandey B.A.

Abstract

In this paper, we have studied harmonic maps on trans-Sasakian manifolds. First it is proved that if F: M1M2 is a Riemannian ϕ-holomorphic map between two trans-Sasakian manifolds such that ξ2 ∈ (Im dF), then F can not be harmonic provided that β2 ≠ 0. We have also found the necessary and sufficient condition for the harmonic map to be constant map from Kaehler to trans-Sasakian manifold. Finally, we prove the non-existence of harmonic map from locally conformal Kaehler manifold to trans-Sasakian manifold.

Lobachevskii Journal of Mathematics. 2016;37(2):185-192
pages 185-192 views

Stability of Gorenstein X-flat modules

Selvaraj C., Umamaheswaran A.

Abstract

In this paper we introduce the notion of Gorenstein X-flat R-module and study a kind of stability of the class of Gorenstein X-flat R-modules. A ring R is called right GXF-closed if the class of all Gorenstein X-flat right R-modules is closed under extensions. We give an answer for the following natural question in the setting of a right GXF-closed ring R: Given an exact sequence of Gorenstein X-flat right R-modules G = · · ·→G1G0G0G1 →· · · such that the complex GRH is exact for each Gorenstein X-injective left R-module H, is themodule M:= im(G0G0) a Gorenstein X-flat R-module?

Lobachevskii Journal of Mathematics. 2016;37(2):193-203
pages 193-203 views

Cohomogeneity one anti de Sitter space AdSn+1

Vanaei M.J., Kashani S.M., Straume E.

Abstract

In this paper we study the anti de Sitter space AdSn+1 under a cohomogeneity one action of a connected closed Lie subgroup G of the isometry group. Among various results, for compact groups we determine the possible acting groups, the orbit space and principal and singular orbits. For noncompact groups it is shown that if there is a principal orbit which is either simply connected or totally umbilic, then there is only one orbit type. Furthermore, in the totally umbilic case, all orbits are congruent to AdSn.

Lobachevskii Journal of Mathematics. 2016;37(2):204-213
pages 204-213 views

Lutz filtration as a Galois module

Vostokov S., Nekrasov I., Vostokova R.

Abstract

In the paper, we consider a formal module F(ML) and its Lutz filtration MLML2ML3 ⊃..., where K is a finite extension of the field of p-adic numbers Qp, L/K is a normal extension without higher ramification with Galois group G = Gal(L/K), F(X, Y) is a formal group over a ring of integers OK with finite height. We study its structure as Z[G]-modules. The main result is contained in Theorem 4.

Lobachevskii Journal of Mathematics. 2016;37(2):214-221
pages 214-221 views

Quantum Hashing. Group approach

Ziiatdinov M.

Abstract

In this paper we consider a generalization of quantum hash functions for arbitrary groups. We show that quantum hash function exists for arbitrary abelian group. We construct a set of “good” automorphisms—a key component of quantum hash funciton. We prove some restrictions on Hilbert space dimension and group used in quantum hash function.

Lobachevskii Journal of Mathematics. 2016;37(2):222-226
pages 222-226 views

This website uses cookies

You consent to our cookies if you continue to use our website.

About Cookies