Editorial backlog
- Arabov M.K., Mukhamadiev E.M., Nurov I.D., Sobirov H.I. SIGNS OF EXISTENCE OF LIMITING CYCLES IN THE SECOND ORDER DIFFERENTIAL EQUATIONS
Status: accepted в т.9 №2
Abstract. This article takes
consideration into the discovery of the limiting cycles in neighborhood
of stationary point of the non - smooth second order differential equation. New conditions are found for coefficient of the equation
which ensure the existence of a limiting cycle.
On the basis of taken results was made sector division in a plane.
Created a package of programs for drawing phase portraits in appropriate sectors.
Date of submission: 19 Aprel 2016 г.
- Klyachin A.A. On continuity and differentiability of the maximum values of functions
Status: reviewing
Abstract. This article discusses the functions which are the maximum values of continuous functions on compact subsets of families. These functions are used, for example, in the study of the geometric structure of the equilibrium of different surfaces -- minimal surfaces, surfaces of constant mean curvature, etc. In this paper we find conditions under which such functions are continuous and differentiable.
Date of submission: 17 May 2016 г.
- Oreshina M.N. Spectral decomposition of a normal operator in a real Hilbert space
Status: reviewing
Abstract. Unbounded normal operators acting in a real Hilbert space are considered. In this article we carry over the classic results of the spectral theory to the case of such operators.
The questions connected with the complexification and decomplexification of normal operators are discussed.
We present two real variants of the spectral decomposition and the real functional calculus theorems for unbounded normal operators
acting in a real Hilbert space.
Date of submission: 22 May 2016 г.
- Khasanov Yu.Kh., Shakiriv I.A. BILATERAL EVALUATION OF THE NORM OF THE FOURIER OPERATOR
Status: reviewing
Abstract. The lower and the upper uniform estimates of the Lebesgue constants of the classical Fourier operator are not final. A new and more simple integral representation received for it, then on the basis of which the problem of its top assessment is completely solved and the known lower assessment is improved.
Date of submission: 14 July 2016 г.
- Salo T.M., Skaskiv O.B. The minimum modulus of gap power series and h-measure of exceptional sets
Status: reviewing
Abstract. For an entire function of the form
$f(z)=\sum_{k=0}^{+\infty}f_kz^{n_k}$, where $(n_k)$ is a strictly
increasing sequence of non negative integers, we establish
conditions when the relations
$$
M_f(r)=(1+o(1)) m_f(r),\quad M_f(r)=(1+o(1))\mu_f(r)
$$
is true as $r\to+\infty$ outside some set $E$ such that $\text{\rm
h-meas }(E)=\int_{E}\frac{dh(r)}{r}<+\infty$, where $h(r)$ is positive continuous function
increasing to $+\infty$ on $[0,+\infty)$ with non-decreasing
derivative, and $M_f(r)=\max\{|f(z)|\colon |z|=r\},\
m_f(r)=\min\{|f(z)|\colon |z|=r\},\
\mu_f(r)=\max\{|f_k|r^{n_k}\colon k\geq 0\} $ the maximum modulus,
the minimum modulus and the maximum term of $f,$ respectively.
Date of submission: 22 July 2016 г.
- Mitrokhin S.I. Об исследовании дифференциального оператора с суммируемым потенциалом с разрывной весовой функцией
Status: accepted в т.0 №0
Abstract. В работе предлагается новый подход к исследованию дифференциальных операторов с разрывной весовой функцией. Изучены спектральные свойства дифференциального оператора, заданного на конечном отрезке, с разделенными граничными условиями, с суммируемым потенциалом, с условиями <<сопряжения>> в точке разрыва весовой функции. При больших значениях спектрального параметра получена асимптотика фундаментальной системы решений соответствующего дифференциального уравнения, с помощью которой выведено уравнение на собственные значения изучаемого дифференциального оператора. Изучена индикаторная диаграмма и найдена асимптотика собственных значений исследуемого оператора.
Date of submission: 25 Avgust 2016 г.
- Khushtova F.G. The first boundary value problem in the half-strip for a differential equation with Bessel operator and partial derivative of Riemann-Liouville
Status: reviewing
Abstract. We study the first boundary value problem in the half-strip for a differential equation with Bessel operator and partial derivative of Riemann-Liouville. The representation of the solution in the case of the zero side condition found in terms of the integral transform with the Wright's function at the kernel. Uniqueness of the solution is proved in the class of functions that satisfy the analogue of Tikhonov's condition.
Date of submission: 16 September 2016 г.
- Khrystiyanyn A.Y., Lukivska D.V. Quasi-elliptic functions
Status: reviewing
Abstract. We investigate quasi-elliptic functions (i. e. certain generalization of elliptic functions). For this class of functions analogues of
$\wp$, $\zeta$ and $\sigma$ Weierstrass functions are constructed and relation between quasi-elliptic and $p$-loxodromic functions is obtained.
Date of submission: 27 September 2016 г.
- Krivosheyeva O.A. Invariant subspaces with spectrum of zero density
Status: reviewing
Abstract. In the paper it is shown that every analytic solution of the homogeneous convolution equation with the characteristic function of a minimal exponential type in the domain of its existence is represented as the series of exponential polynomials which converges uniformly on compact subsets of this domain.
Date of submission: 31 October 2016 г.
- Garifullin R.N., Yamilov R.I. On the integrability of a discrete analogue of the Kaup–Kupershmidt equation
Status: accepted в т.0 №0
Abstract. We study a new example of equation obtained as a result of a recent generalized symmetry classification of differential-difference equations defined on five points of one-dimensional lattice. We have established that in the continuous limit this new equation goes into the well-known Kaup–Kupershmidt equation. We have also proved its integrability by constructing an $L-A$ pair and conservation laws. Moreover, we present a possibly new scheme for deriving conservation laws from $L-A$ pairs.
Date of submission: 12 December 2016 г.
- Baizaev S., Rakhimova M.A. О некоторых функциональных уравнениях в
пространствах Шварца и их приложениях
Status: reviewing
Abstract. В статье изучается вопросы нетривиальной
разрешимости функциональных уравнений вида
$$(B+r^{2}E)u(r,\theta)=0$$
где $B -$ постоянная комплексная матрица порядка $n$, $E -$
единичная матрица порядка $n$, $(r,\theta) -$ полярные координаты в
пространствах Шварца. Получены многообразия всех решений из
указанных пространств и даны приложения результатов к задачам
нахождения решений полиномиального роста ряда классов эллиптических
систем и переопределенных систем.
Date of submission: 12 December 2016 г.
- Ishkina Sh.Kh. Combinatorial bounds of overfitting for threshold classifiers
Status: reviewing
Abstract. Tightening generalization bounds is a fundamental objective of statistical learning theory.
However, accurate and computationally efficient bounds are still unknown even for very simple cases.
In~this paper, we consider one-dimensional threshold decision rules.
We~use the framework of combinatorial theory of overfitting,
which is based on a single probabilistic assumption that
all partitions of a~set of objects into an observed training sample and a~hidden test sample can occur with equal probability.
We~propose a~polynomial algorithm for computing both probability of overfitting and complete cross-validation.
Date of submission: 21 December 2016 г.
- Kalyakin L.A. Adiabatic approximation for a model of resonance capture
Status: accepted в т.9 №2
Abstract. Две модельные задачи о захвате в резонанс
анализируются методом усреднения, который приводит к адиабатическому
приближению в главном члене асимптотики. Основной целью является приближенное
описание области захвата в резонанс. Эта область зависит от дополнительного
параметра, входящего в уравнения. Демонстрируется непригодность
адиабатического приближения, когда область захвата становится узкой. В этом
случае требуется значительное изменение метода усреднения.
Date of submission: 26 December 2016 г.
- Galakhov E.I., Salieva O.A. Условия отсутствия решений некоторых неравенств и систем с функциональными параметрами и сингулярными коэффициентами на границе
Status: accepted в т.0 №0
Abstract. We obtain sufficient conditions for nonexistence of positive solutions of some nonlinear elliptic inequalities and systems that contain the $p(x)$-Laplace operators with variable power exponents and coefficients possessing singularity on the boundary.
Date of submission: 28 December 2016 г.
- Belaidi B., Saidani M. On The Growth of Solutions of Some Higher Order Linear Differential Equations With Meromorphic Coefficients
Status: reviewing
Abstract. In this paper, we study the growth of meromorphic solutions of
the differential equation ....
Date of submission: 06 January 2017 г.
- Khan N.U., Usman T. CERTAIN GENERATING FUNCTIONS OF
HERMITE-BERNOULLI-LEGENDRE POLYNOMIALS
Status: reviewing
Abstract. In this paper, we introduce a new class of generating functions for Hermite-
Bernoulli-Legendre polynomials and investigate certain implicit summation formulas by
using different analytical means and applying generating function. We also introduce bi-
lateral series associated with the newly-introduced generating function by appropriately
specializing a number of known or new partly unilateral and partly bilateral generating
functions.
Date of submission: 27 January 2017 г.
- Shukla I. Simultaneous Quadruple Series Equations Involving Konhauser Biorthogonal Polynomials
Status: reviewing
Abstract. Spencer and Fano [11] used the biorthogonal polynomials (for the
case of k = 2) in carrying out calculations involving penetration of gamma rays
through matter. In the present paper an exact solution of simultaneous quadruple
series equations involving Konhauser – biorthogonal polynomials of first kind
of different indices is obtained by multiplying factor technique due to Noble
[13]. This technique has been modified by Thakare [12] to solve dual series
equations involving orthogonal polynomials which led to disprove a possible
conjecture of Askey [6] that dual series equations involving Jacobi polynomials
of different indices cannot be solved. In this paper the solution of simultaneous
quadruple series equations involving generalized Laguerre polynomials also
have been discussed in a particular case.
Date of submission: 28 January 2017 г.
- Salimov R.B. The study of the behavior of the singular integral with the Hilbert kernel near a point of the new weak continuity of the density
Status: accepted в т.0 №0
Abstract. We study the behavior of a singular integral with the Hilbert kernel near a fixed point, where the density vanishes as a negative exponent of the logarithm module of the distance from the fixed point to a variable one at the new conditions.
Date of submission: 08 February 2017 г.
- Murtazina S.A., Fazlytdinov M.F., Shevtsova T.V., Yumagulov M.G. Operator methods for computing Lyapunov quantities in
the problems on the local bifurcations of dynamical systems
Status: accepted в т.0 №0
Abstract. This work proposes new formulas to
calculate Lyapunov quantities in problems of major scripts of local
bifurcations of dynamical systems. Considered a dynamical system,
described by differential equations, and point mappings. The
proposed formulas are obtained from the general operational method
of the study of local bifurcations and do not require transition to
normal forms and use theorems about the central diversity.
Date of submission: 06 Mart 2017 г.
- Kononova A.A. On measures generating orthogonal polynomials with similar asymptotic behavior of the ratio near infinity
Status: accepted в т.0 №0
Abstract. We consider perturbations of orthogonality measure of the system of polynomials that do not change (in some sense) the asymptotical behavior of the ratio of corresponding orthogonal polynomials.
The support of the measure consists of the finite number of Jordan curves and may also contain a finite number of mass-points out of the polynomial convex hull of the support of the absolute continuous part of the measure.
The problem is a generalization of the problem of compactness of the perturbation of Jacobi operator generated by the perturbation of its spectral measure. A condition, necessary (or necessary and sufficient under some additional restriction) for the stability of the asymptotical behavior of the corresponding orthogonal polynomials is found.
Date of submission: 09 Mart 2017 г.
- Halder S., Sahoo P. UNIQUENESS OF MEROMORPHIC FUNCTIONS CONCERNING DIFFERENTIAL POLYNOMIALS SHARING A SET
Status: reviewing
Abstract. In this paper, we investigate the uniqueness of meromorphic functions whose
certain nonlinear differential polynomials share a set of values with finite weight and obtain
some results that generalize and improve the recent results due to H.Y. Xu [J. Computational
Analysis and Applications, 16(2014), 942-954].
Date of submission: 27 Mart 2017 г.
- Nuraliev F.A., Hayotov A.R., Shadimetov Kh.M. Optimal quadrature formulas with derivatives in Sobolev space
Status: reviewing
Abstract. In the present paper the problem of construction of optimal
quadrature formulas in the sense of Sard in the space
$L_2^{(m)}(0,1)$ is considered. Here the quadrature sum consists of
values of the integrand at nodes and values of the first and the third
derivatives of the integrand at the end points of the integration
interval. The coefficients of optimal quadrature formulas are
found and the norm of the optimal error functional is calculated
for arbitrary natural number $N\geq m-3$ and for any $m\geq 4$ using S.L.
Sobolev method which is based on the discrete analogue of the
differential operator $d^{2m}/dx^{2m}$. In particular, for $m=4,\
5$ optimality of the classical Euler-Maclaurin quadrature formula
is obtained. Starting from $m=6$ new optimal quadrature formulas
are obtained. At the end of this work some numerical results are presented.
Date of submission: 30 Mart 2017 г.
- Krivosheyev A.S., Kuzhaev A.F. On a Leontiev-Levin theorem
Status: reviewing
Abstract. In this work we investigate relations between different densities of a positive sequence and variables related to them. The results are used to generalise classical proposition on completeness of exponential monomials systems with positive exponents in a convex domain when these exponents haven't density. That proposition was obtained by A.Leontiev and B.Levin independently. This generalisation is given for sufficiently wide class of convex domains, for example, with vertical or horizontal symmetry axes.
Date of submission: 30 Mart 2017 г.
- Rathod A. Nevanlinna’s Five-values Theorems for Algebroid Functions
Status: reviewing
Abstract. By using the second main theorem of the algebroid function, we inves-
tigate the problem on two algebroid functions partially sharing five or more values
and that improve and generalize the previous results given by Xuan and Gao.
Date of submission: 06 Aprel 2017 г.
- Khashimov A.R. ЭНЕРГЕТИЧЕСКИЕ ОЦЕНКИ ДЛЯ РЕШЕНИЙ КРАЕВЫХ
ЗАДАЧ УРАВНЕНИЯ ТРЕТЬЕГО ПОРЯДКА С КРАТНЫМИ ХАРАКТЕРИСТИКАМИ
Status: reviewing
Abstract. В статье рассмотрена первая краевая задача для уравнения третьего порядка с кратными характеристиками. Для обобщенного решения уравнения установлена энергетические оценки типа аналога принципа Сен-Венана. С помощью этой оценки выявлены
наибольшее класс единственности решений краевых задач в зависимости от геометрических характеристик области.
Date of submission: 07 Aprel 2017 г.
- Shabat A.B., Эфендиев M.H. О приложениях формулы Фаа-ди-Бруно
Status: reviewing
Abstract. Two new modifications of the classical Faa-di-Bruno formula
are constructed and applications of the obtained formulas in the theory of
integrability of nonlinear partial differential equations
Date of submission: 08 Aprel 2017 г.
- Stepanova I.V. Symmetries of heat and mass transfer equations in viscous fluids
Status: reviewing
Abstract. The paper is devoted to description of results of application of classical Lie-Ovsyannikov theory
to study of heat and mass transfer equations in viscous liquids. Group properties of equations of
convective and molecular heat and mass transfer are under consideration. The author analyzed 124 papers and
monographs be concerning to mentioned problem.
Date of submission: 10 Aprel 2017 г.
- Singh D.K., Singh P. Wright Function Associated with
Fractional Calculus
Status: reviewing
Abstract. With the marvelous light of fractional calculus, the study of this paper
is based on Wright function and Raizada polynomial.
Date of submission: 17 Aprel 2017 г.
- Zhukova N.I. The influence of stratification on groups of conformal transformations of pseudo-Riemannian orbifolds
Status: reviewing
Abstract. Groups of conformal transformations of $n$-dimensional pseudo-Riemannian
orbifolds $({\mathcal N},g)$ are investigated for $n\geq 3$. It is shown that a conformal pseudo-Riemannian
geometry is induced on each stratum of that orbifold. For $k\in\{0,1\}\cup\{3,...,n-1\}$ exact estimates
of dimensions of the conformal transformation groups of $n$-dimensional pseudo-Rieman\-ni\-an orbifolds
admitting $k$-dimensional strata with essential conformal trans\-for\-ma\-tion groups are obtained.
Date of submission: 08 May 2017 г.
- Kachalov V.I. Pseudoholomorphic functions and their application
Status: reviewing
Abstract. An analysis of asymptotic methods for solving singularly perturbed problems shows that the solutions obtained by means of these solutions depend in two ways on the small parameter: regularly and singularly. This dependence is particularly clearly demonstrated by the method of regularization of S.A.\,Lomov. Moreover, the regularized solu\-tions of singularly perturbed equations can converge in the usual sense. In this connection, it became necessary to study a special class of functions, pseudoholomorphic functions. This is a very important part of the analy\-sis, it is intended to substantiate the main points of the so-called analytic theory of singular perturbations. On the other hand, the relevance of the theory in question is also dictated by the fact that pseudoholomorphic functions, unlike holomorphic functions, are determined when the condi\-tions of the implicit function theorem are violated.
Date of submission: 16 May 2017 г.
- Trynin A.Yu. Uniform convergence of sync-approximations on the functional
class
Status: reviewing
Abstract. We obtain a uniform convergence inside the interval (0, \ pi) of the values of the Lagrange-Sturm-Liouville operators for functions from the class. The class is defined by means of one-way moduli of continuity and change
Date of submission: 18 May 2017 г.
- Bobodzhanov A.A., Safonov V.F. Regularized asymptotics of solutions of integro-differential partial differential equations with rapidly varying kernels
Status: reviewing
Abstract. The method of Lomov regularization is generalized to partial differential equations with integral operators, the kernel of which contains a rapidly varying exponential factor. The case when the upper limit of the integral operator coincides with the differentiation variable is investigated. For such problems, an algorithm for constructing regularized asymptotics develops. In contrast to the work of Imanaliev M.I., where for analogous problems with slowly varying nuclei only the limit transition is investigated when the small parameter tends to zero, an asymptotic solution of any order (with respect to the parameter) is constructed here.
Date of submission: 19 May 2017 г.
- Kulaev R.Ch., Shabat A.B. Some properties for Jost functions of a Schr\"odinger equation with potential, which is a distribution
Status: reviewing
Abstract. Работа посвящена задаче кардинального расширения пространства потенциалов в обратной задаче рассеяния для линейного уравнения Шр\"едингера на числовой прямой. Рассматривается оператор Шр\"едингера с потенциалом из пространства обобщенных функций. Это расширение включает в себя не только потенциалы типа $\delta$-функции, но и экзотику типа функции Кантора. На этом пути устанавливаются условия существования и единственности решений Йоста, изучаются их свойства.
Date of submission: 23 May 2017 г.
- Fedotov A.I. Hermite-Fejer polynomials as an approximate solution of the singular integro-differential equations
Status: reviewing
Abstract. An approximate method for solving singular integro-differen-tial equations
in periodic case is justified. An approximate solution is sought in a form of
Hermite-Fejer polynomials. The convergence of the method is proved and the errors are estimated.
Date of submission: 24 May 2017 г.
- Konechnaya N.N., Mirzoev K.A. Asymptotics of solutions of a class of linear differential equations
Status: accepted в т.0 №0
Abstract. In this paper the main term of asymptotics of some fundamen- tal system of solutions of a class of linear differential equations of arbitrary order $\tau y=\lambda y$ at infinity is found, where $\lambda$ is a fixed complex number. In this case, the conditions imposed on the coefficients of the differential equation are not related to their smoothness, but only provide a certain power-law growth of the coefficients at infinity. The results obtained are applied to the spectral analysis of the corresponding singular differential operators, including in the case when the expression $ \tau $ is a product of two differential expressions.
Date of submission: 26 May 2017 г.
- Kachalov V.I. On the holomorphic regularization of strongly nonlinear singularly perturbed problems
Status: reviewing
Abstract. The method of holomorphic regularization, which is a logical extension of the Lomov method, allows one to construct solutions of nonlinear singularly perturbed initial problems in the form of series converging in the usual sense in powers of a small parameter. The method itself is based on a generalization of the Poincare decomposition theorem: in the regular case, solutions depend holomorphically on a small parameter, in the singular case the first integrals inherit this dependence.
Date of submission: 29 May 2017 г.
- Zikkos E. A Taylor-Dirichlet series with no singularities on its abscissa of convergence
Status: reviewing
Abstract. In this paper it is proved that given any non-negative real number $d$,
there exists a Taylor-Dirichlet series of the form
\[
\sum_{n=1}^{\infty} \left(\sum_{k=0}^{\mu_n-1}c_{n,k}
z^k\right) e^{\lambda_n z},\quad c_{n,k}\in \mathbb{C}
\]
with no singularities on its abscissa of convergence, such that its associated multiplicity-sequence $\Lambda=\{\lambda_n,\mu_n\}_{n=1}^{\infty}$ has the following properties:
\noindent
(1) the terms of $\Lambda$ are positive real numbers and uniformly separated,
\noindent
$(\inf_{n\in\mathbb{N}}(\lambda_{n+1}-\lambda_n)>0)$,
\noindent
(2) $\Lambda$ has density equal to $d$, $\left(\lim_{t\to\infty}\frac{\sum_{\lambda_n\le t}\mu_n}{t}=d<\infty\right)$,
\noindent
(3) the multiplicities of the terms of $\Lambda$ are unbounded, $(\mu_n\not=O(1))$.
The proof is based on the fact that for this sequence $\Lambda$
its Krivosheev characteristic $S_{\Lambda}$ is negative.
We remark that when $\mu_n=1$ for all $n\in\mathbb{N}$ the result is false by a well known theorem of P\'{o}lya.
Date of submission: 30 May 2017 г.
- Vinnitskii B.V., Sharan V.L., Sheparovych I.B. About some interpolation problem in the class of functions of exponential type in a half-plane
Status: reviewing
Abstract. The conditions of solvability of the
interpolation problem $f(\lambda_{k} )=d_{k} $ are found in the
class of functions of exponential type. This results are applied
to research of some problem of the function's splitting.
Date of submission: 01 June 2017 г.
- Klimentov S.B. About Isomorphism of Some Integro-differential Operators
Status: reviewing
Abstract. In this work representations of <> for solutions of the linear general elliptic system of the first order in the unit circle are considered. The isomorphism of corresponding operators is established in Banach spaces $C^k_\alpha (\overline D) $ and $W^k_p (\overline D) $, $k\geq $1, $0 <\to alpha <$1, $p> $2. These results develop and supplement B.V. Boyarsky's works where representa\-tions of <> where obtained. Also this work supplements author’s results on representations of <> with more difficult operators.
Date of submission: 02 June 2017 г.
- Braichev G.G. Two-sided estimates of the relative growth of functions and their derivatives
Status: reviewing
Abstract. В работе дано расширенное изложение доклада автора, подготовленного для международной математической конференции по теории функций, посвященной 100-летию чл.-корр. АН СССР А.\,Ф.~Леонтьева. Установлены равномерные двусторонние оценки относительного роста производных двух функций на основе информации об относительном росте самих функций. Рассмотрены примеры применения полученных результатов к исследованию поведения целых функций.
Date of submission: 03 June 2017 г.
- Eliseev A.G., Ratnikova T.A., Shaposhnikova D.A. Singularly perturbed systems of Volterra integral equations of the second kind
Status: reviewing
Abstract. In this paper we study the initialization problem for singularly perturbed systems of Volterra integral equations of the second kind. A general approach to the construction of the regularized asymptotics of singularly perturbed integro-differential equations is described in the papers of S.A. Lomov and his progeny. In this paper, we study the problem of the passage to the limit and the estimate of the remainder in the initialization problem for the original singularly perturbed system of Volterra integral equations. Calculations are given, the class of right-hand sides is determined by the example of one singularly perturbed Volterra integral equation of the second kind.
Date of submission: 07 June 2017 г.
- Shaygardanov Yu.Z. Asymptotics of the solution of an elliptic boundary value problem in neighborhood of the line of the outer touch characteristics of the limit equation
Status: reviewing
Abstract. The article deals with a boundary value problem for elliptic equations of second order with small parameter $\varepsilon>0$ in a bounded region $Q\subset \Bbb R^3$ with smooth boundary $\Gamma :\,\,\, \varepsilon Au-\partial / \partial x_3\, u=f,$ $u|_{\Gamma}=0.$ Under the assumption that the set of points external touch characteristics of the limit equation of the boundary is a smooth closed curve the asymptotic expansion of the solution in a neighborhood of this curve was received.
Date of submission: 09 June 2017 г.
- Rahman S. ON PSEUDO-SLANT SUBMANIFOLDS OF NEARLY LORENTZIAN PARA-SASAKIAN MANIFOLDS
Status: reviewing
Abstract. The object of the present paper is to study pseudo slant submanifolds of nearly Lorentzian para-Sasakian manifolds. The necessary and sufficient conditions on a totally umbilical proper-slant submanifolds are worked out and obtain some interesting results regarding such submanifolds. The integrability condition of the distribution of pseudo -slant submanifolds of nearly Lorentzian para-Sasakian manifolds are also discussed.
Date of submission: 10 June 2017 г.
- Avkhadiev F.G. Estimates of Hardy-Rellich's constants for polyharmonic operators and their generalizations
Status: reviewing
Abstract. We prove lower estimates for functionals defined as maximal constants in Hardy and Rellich type inequalities for polyharmonic opera-tors and their generalizations on domains of the Euclidean space. In proofs we essentially use an integral identity by Ladyzhenskaya and its generalization to the case of polyharmonic operators.
Date of submission: 14 June 2017 г.
- Poluboyarova N.M. On the instability of extremals of the potential energy functional
Status: reviewing
Abstract. In this paper study has been done on problem of stability and instability of the potential energy functional. By stability we mean the sign-definiteness of the second variation. The expression for the second variation of the functional is calculated. With the capacitive method it is obtain to make the feature of instability extremals. Proved that stability parabolic extremals are planes. We have written the equation of extremals and the second variation of the functional for n-dimensional surfaces of revolution.
Date of submission: 18 June 2017 г.
- Sukhov A.B. Levi-flat world: a survey of local theory
Status: reviewing
Abstract. This expository paper concerns local properties of Levi-flat real analytic manifolds with singularities.
Date of submission: 19 June 2017 г.
- Novokshenov V.Yu. Discrete integrable equations and special functions
Status: reviewing
Abstract. A generic scheme based on the Riemann-Hilbert (RH) problem
theory is proposed for description of classical special
functions satisfying difference equations. Those functions comprise gamma- and zeta functions, as well as orthogonal polynomials with corresponding recurrence relations. It ia shown that all difference equations are the compatibility conditions of certain Lax pair coming from the RH problem. On the other hand, the solutions of RH problem provide analitic properties of the special functions as well as find new functions pretending for the name of special ones. Those are solutions of discrete Painlev\'e equations.
Date of submission: 21 June 2017 г.
- Imomov A.A., Meyliyev A.H., Тухтаев E.E. Об уточнении одной предельной теоремы из теории критических ветвящихся процессов с дискретным временем
Status: reviewing
Abstract. We consider critical Galton-Watson branching process. The generating function of distribution of one particle has the infinite second moment, but its tail is regularly varying in sense of Karamata. The speed rate of convergence of distribution of process on nonzero trajectories to the limit law is established.
Date of submission: 22 June 2017 г.
- Berdellima A. ON A CONJECTURE OF KHABIBULLIN ABOUT A PAIR OF INTEGRAL INEQUALITIES
Status: reviewing
Abstract. It is known that in general Khabibullin’s conjecture is not true. Sharipov [8]
constructed a counterexample when $n = 2$ and $\alpha = 2$. In this paper we develop a method
of how to construct a counterexample for the more general case $n > 2$ and $\alpha > 1/2$.
Date of submission: 24 June 2017 г.
- Gaisin A.M., Gaisina G.A. Estimates of the growth and decrease of functions in the theorem of Macintyre--Efgrafov's type
Status: reviewing
Abstract. The method of estimating the sum of the Dirichlet series on the system of segments $[\alpha, \, \alpha + \delta] \, (\alpha> 0$ is fixed, $\delta> 0$ --- any) based on inequalities for extremal functions from some non-quasianalytic Carleman’s class is given in this paper. An estimate of the rate of tends to zero function in an example of the Macintyre--Evgrafov’s type is proved.
Date of submission: 27 June 2017 г.
- Isaev K.P., Trunov K.V., Youlmukhametov R.S. Representation of functions in locally convex subspaces of $A^\infty (D)$ by series of exponentials
Status: reviewing
Abstract. Let $D$ be a bounded convex domain on the complex plane. We consider some locally convex subspaces in the space of analytic functions in $ D $ that are infinitely differentiable in $ \overline D $. It is proved that such functions are representable by series of exponentials converging in the topology of these subspaces.
Date of submission: 27 June 2017 г.
- Baskakov A.G., Uskova N.B. Linear differential operator with an involution as generator of group of operators
Status: reviewing
Abstract. We consider mixed problem for first order differential equation with involution.
By the method of similar operators, he differential operator, which defined by this differential
equation, is transformed in orthogonal direct sum of operators. By the main theorem we construct group of operators and
we describe the weak solutions of this problem. We use this theorem for Fourier method.
Date of submission: 29 June 2017 г.
- Garayev M., Guediri H., Sadrawi H. New Characterizations of Bloch spaces, Bers-type and Zygmund-type spaces and
Related Questions
Status: reviewing
Abstract. We give in terms of Berezin symbols new characterizations of\ the Bloch spaces
$\mathcal{B}$ and $\mathcal{B}_{0},$ Bers-type and the Zygmund-type spaces of
analytic functions on the unit disc $\mathbb{D}$ of the complex plane
$\mathbb{C}.$ Moreover, we discuss some properties of Toeplitz operators on
the Bergman space $L_{a}^{2}(\mathbb{D}).$ A new characterization of\ some
function space with variable exponents is also given.
Date of submission: 29 June 2017 г.
- Kopachevsky N.D., Tsvetkov D.O. Малые движения идеальной стратифицированной жидкости со свободной поверхностью, полностью покрытой крошеным льдом
Status: reviewing
Abstract. Let a rigid immovable vessel be partially filled with an ideal incompressible stratified fluid. We assume that in an
equilibrium state the density of a fluid is a function of the vertical variable $x_3,$ i.e., $\rho_0=\rho_0(x_3).$ In this case the
gravitational field with constant acceleration $\vec g=-g\vec e_3$ acts on the fluid, here $g>0$ and $\vec e_3$ is unit vector of the vertical
axis $Ox_3,$ which is directed opposite to $\vec g.$ Let $\Omega$ be the domain filled with a fluid in equilibrium state, $S$ be rigid wall of
the vessel adherent to the fluid, $\Gamma$ be a free surface completely covered with a crumbled ice.
The initial boundary value problem is reduced to the Cauchy problem
\begin{equation*}
\begin{split}
&\mathcal A \frac{d^2x}{dt^2} + \mathcal C x = f(t),
\quad x(0)=x^0, \quad x^{'}(0)=x^1, \\
&0<< \mathcal A= \mathcal A^{*} \in \mathcal L(\mathcal H),
\quad
0 \leq \mathcal C = \mathcal C^{*} \in \mathcal L(\mathcal H).
\end{split}
\end{equation*}
in some Hilbert space $\mathcal H$. The theorem on strong solvability of initial boundary value problem is proved.
Date of submission: 29 June 2017 г.
- Ivanova О.А., Melikhov S.N., Melikhov Yu.N. On the commutants of differetiation and translation operators
in weighted spaces of entire functions
Status: reviewing
Abstract. We describe continuous linear operators which commute with the
system of partial di?eretiation operators and translation operators in a countable
inductive limits of weighted Frechet spaces of entire functions of several complex varibles.
Date of submission: 30 June 2017 г.
- Shamoyan F.A. АНАЛИТИЧЕСКИЕ ФУНКЦИИ С ГЛАДКИМ МОДУЛЕМ ГРАНИЧНЫХ ЗНАЧЕНИЙ
Status: reviewing
Abstract. Пусть $f$ --- аналитическая функция в единичном круге $D$, непрерывная вплоть до его границы $\Gamma, f(z) \neq 0, z \in D$. Предположим $f$ имеет на $\Gamma$ модуль непрерывности $\omega(|f|,\delta)$. В статье устанавливается оценка $\omega(f,\delta) \leq A\omega(|f|, \sqrt{\delta})$, где $A$ --- некоторое неотрицательное число. Также устанавливается точность данной оценки.
Date of submission: 10 July 2017 г.
- Andriyan S.M., Kroyan A.K., Khachatryan K.A. On Solvability of a Class of Nonlinear Integral Equations in $p$ -adic String Theory
Status: reviewing
Abstract. In this paper a class of nonlinear integral equations, which has direct application in the $ p $ -adic string theory, is studied. The existence of a nontrivial continuous odd and bounded solution on the whole axis is proved. With some additional conditions, the uniqueness of the constructed solution in the certain class of continuous functions is established as well.
Date of submission: 15 July 2017 г.
- Musin I.Kh. On a Hilbert space of entire functions
Status: reviewing
Abstract. A weighted Hilbert space of entire functions of $n$ variables is considered in the paper. The weight function is a convex function on ${\mathbb C}^n$ depending on modules of variables and growing at infinity faster than $a \Vert z \Vert$ for each $a > 0$. The strong dual of this space is described in terms of the Laplace transform of functionals.
Date of submission: 17 July 2017 г.
- RamReddy T., Shalini D., Vamshee Krishna D. THIRD ORDER HANKEL DETERMINANT FOR STAR LIKE
FUNCTIONS OF ORDER $\alpha$
Status: reviewing
Abstract. The objective of this paper is to obtain best possible upper
bound to the third Hankel determinant for the class of starlike functions of
order $\alpha$ ($0 \leq \alpha < 1$), using Toeplitz determinants.
Date of submission: 17 July 2017 г.
- Haslinger F. Pauli operators and the $\overline\partial$-Neumann problem
Status: reviewing
Abstract. We apply methods from complex analysis, in particular the
$\ovprt$-Neumann operator, to investigate spectral properties of Pauli operators.
Date of submission: 17 July 2017 г.
- Muravnik A.B. On Qualitative Properties of Solutions of Quasilinear Parabolic
Equations Admitting Degenerations at Infinity
Status: reviewing
Abstract. We consider the Cauchy problem для for
quasilinear parabolic equations of the kind
$\rho(x)u_t=\Delta u + g(u)|\nabla u|^2,$ where the positive coefficient $\rho$
admits a degeneration at infinity, while the coefficient $g$ either is a continuous function
or admits power singularities such that the power does not exceed one.
The long-time
behavior of (classical) solutions of the specified problem is
investigated.
Date of submission: 21 July 2017 г.
- Zhapsarbayeva L.K., Kanguzhin B.E., Konyrkulzhayeva M.N. Selfadjoint restriction of the maximal operator on the graph
Status: reviewing
Abstract. The paper is devoted to the linear differential operators defined on graphs. In this paper Lagrange formula for second-order differential operator on a graph with Kirchhoff conditions at its internal vertices is derived. The conditions for a selfadjointness of the differential operator on the graph are established.
Date of submission: 24 July 2017 г.
- Ehrgashev T.G. Third Double-Layer Potential for a Generalized Bi-Axially
Symmetric
Helmholtz Equation
Status: reviewing
Abstract. The double-layer potential plays an
important role in solving boundary value problems for elliptic
equations, and in the study of which for a certain
equation, the properties of the fundamental solutions of the given
equation are used. All the fundamental solutions of the
generalized bi-axially symmetric Helmholtz equation were known,
and only for the first one was constructed the theory of
potential. Here, in this paper, we aim at constructing theory of
double-layer potentials corresponding to the third fundamental
solution. By using some properties of one of Appell's
hypergeometric functions in two variables, we prove limiting
theorems and derive integral equations concerning a denseness of
double-layer potentials.
Date of submission: 31 July 2017 г.
- Bandura A.I., Skaskiv O.B. Exhaustion by balls and entire functions of bounded $\mathbf{L}$-index in joint variables
Status: reviewing
Abstract. We prove criteria of boundedness of $\mathbf{L}$-index in joint variables which describe local behavior of partial derivatives
on sphere in $\mathbb{C}^n.$
Some obtained results are new even for entire functions
of bounded index in joint variables, i. e. $\mathbf{L}(z)\equiv 1,$
because we used an exhaustion of $\mathbb{C}^n$ by balls
instead an exhaustion of $\mathbb{C}^n$ by polydiscs.
Date of submission: 08 Avgust 2017 г.
- Baskakov A.G., Dikarev E.E. Spectral Theory of Functions in Research of Partial Differential Operators
Status: reviewing
Abstract. Spectral properties of differential operators with
constant coefficients defined on subspaces of space of bounded continuous functions are studied. Necessary and sufficient conditions of invertibility are
obtained under condition of regularity at the infinity (ellipticity type conditions) of polynomial which describes such operators. Spectrum, images and kernels are described. Conditions of compactness of resolvent of differential operators are obtained. Main results are obtained by methods of harmonic analysis and spectral theory of Banach modules.
Date of submission: 10 Avgust 2017 г.
- Davletov D.B., Davletov O.B., Kozhevnikov D.V., Sadykova R.R. Asymptotics of the eigenvalue of the Steklov type boundary value
problem for the Laplace operator in a half-strip with a small hole.
Status: reviewing
Abstract. The paper considers the problem of the
Steklov type for the Laplace operator in a half-strip containing a
small cavity. On lateral boundaries and on the boundary of a small
hole conditions are set Dirichlet, and on the basis of the
half-strip -- the Steklov spectral condition. An asymptotic
expansion of the eigenvalue to within a small parameter ("Hole
diameter"), converging to a simple eigenvalue the limiting problem
(without a small cavity) is constructed and rigorously proved.
Date of submission: 11 Avgust 2017 г.