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Квазиклассическое приближение для разностных уравнений 2-ого порядка в неограниченной области
С. 6–7.
In this paper, we consider a linear homogeneous difference equation of the 2nd order with smooth coefficients. It is known that there are the several solutions to such equation. We have constructed explicit restrictions on the smoothness and growth of the coefficients of the equation, under which the solution retains the WKB form in an unbounded domain that does not contain pivot points and singularity points. The asymptotics of Laguerre polynomials are constructed for simultaneously large values of the argument and the order of the polynomials using proven asymptotic estimates as an application example.
A. V. Pereskokov, Journal of Mathematical Sciences 2025 Vol. 291 No. 4 P. 544–553
We study the eigenvalue problem for a perturbed resonance oscillator. We find asymptotic
expansions of coherent states of the algebra su(2). We show that the asymptotic
eigenfunctions are localized near a circle and construct an expansion of asymptotic eigenfunctions
near this circle. ...
Added: December 7, 2025
Vybornyi E., Rumiantseva S., Математические заметки 2024 Т. 116 № 6 С. 862–880
In this paper, we consider the problem of constructing a semiclassical asymptotic estimate of the splitting between a pair of close lower-lying energy levels for a quadratic operator defined on the irreducible representation of the Lie algebra su(1,1). In Darboux coordinates on the hyperboloid the Hamiltonian defines the landscape of a symmetric double well. It ...
Added: November 12, 2024
Sofia V. Rumyantseva, Acta Applicandae Mathematicae 2025 Vol. 195 Article 4
Difference equations play a crucial role in a wide array of mathematical and physical tasks. In this article, we focus on the analysis of a second order linear homogeneous difference equation with smooth coefficients via WKB method. It is well-known that such equations exhibit two WKB solutions in a segment devoid of turning and singular ...
Added: November 2, 2024
А.В. Перескоков, В кн.: Современные методы теории краевых задач.: М.: МАКС Пресс, 2018. С. 170–171.
В работе найдены асимптотические решения двумерных уравнений типа Хартри, локализованные вблизи отрезков. ...
Added: December 15, 2023
Перескоков А.В., В кн.: НЕКОТОРЫЕ ПРОБЛЕМЫ ТЕОРИИ ВОЗМУЩЕНИЙ И МЕТОД РЕГУЛЯРИЗАЦИИ.: М.: Издательство МЭИ, 2023. С. 55–72 .
Рассматривается задача об эффекте Зеемана для атома водорода в магнитном
поле с использованием неприводимых представлений алгебры с квадратичными
коммутационными соотношениями Карасева — Новиковой. Найдена асимптотика серии собственных значений и асимптотические собственные функции вблизи
нижних границ ...
Added: December 12, 2023
Lomonosov T., / Series arXiv "math". 2023. No. 2307.07182.
In this paper, an algebraic modification of the method of undetermined coefficients for solving nonhomogeneous linear stationary difference equations for quasipolynomial right-hand sides is proposed. Although the classical method of undetermined coefficients is well-known in both differential equations and difference equations case, its application in the difference equations case is severely limited. For example, it ...
Added: October 30, 2023
Vybornyi E., Rumiantseva S., Математические заметки 2022 Т. 112 № 5 С. 665–681
The paper considers the problem of constructing semiclassical asymptotics of tunnel splitting of the spectrum of an operator given on an irreducible representation of the Lie algebra su(1, 1). It is assumed that the operator is a quadratic function of the generators of the algebra. Coherent states and coherent unitary transformation are presented, which make ...
Added: November 7, 2022
Pereskokov A., В кн.: Современные методы теории функций и смежные проблемы.: Воронеж: Издательский дом ВГУ, 2021. С. 236–236.
Рассматривается задача на собственные значения для двумерного оператора
Хартри с малым параметром перед нелинейностью. Найдены асимптотические собственные значения и асимптотические собственные функции вблизи локального
максимума собственных значений в спектральных кластерах, которые образуются
около собственных значений невозмущенного оператора. ...
Added: December 14, 2021
Pereskokov A., Journal of Mathematical Sciences 2021 Vol. 259 No. 2 P. 244–263
We study the Zeeman–Stark effect problem in the hydrogen atom located in an electromagnetic
field by using irreducible representations of the Karasev–Novikova algebra
with quadratic commutation relations. We find asymptotics of a series of eigenvalues
and the corresponding eigenfunctions near the lower boundaries of spectral clusters. ...
Added: December 6, 2021
Spiridonov V., Sarkissian G. A., / Series arXiv "math". 2021. No. arXiv:2105.15031.
General reduction of the elliptic hypergeometric equation to the level of complex hypergeometric functions is described. Derived equation is generalized to the Hamiltonian eigenvalue problem for new rational integrable N-body systems emerging from particular degenerations of the elliptic Ruijsenaars and van Diejen models. ...
Added: November 9, 2021
Булеков А. А., Journal of Physics: Conference Series 2021 Vol. 1740 Article 012069
The paper is devoted to the construction of spectral series and the estimation of the approximation accuracy for the operator of the Curie – Weiss model. In the course of work, the operator is reduced to a tridiagonal form in the subspace of the original space, then to a secondorder difference equation. The admissibility of ...
Added: June 9, 2021
A. V. Pereskokov, Theoretical and Mathematical Physics 2020 Vol. 205 No. 3 P. 1652–1665
We consider the eigenvalue problem for the two-dimensional Hartree operator with a small nonlinearity
coefficient. We find the asymptotic eigenvalues and asymptotic eigenfunctions near a local maximum of
the eigenvalues in spectral clusters formed near the eigenvalues of the unperturbed operator. ...
Added: December 7, 2020
Migaeva A. S., Pereskokov A., Journal of Mathematical Sciences 2020 Vol. 251 No. 6 P. 850–875
We study the Zeeman-Stark effect in the hydrogen atom located in an electromagnetic field by using irreducible
representations of an algebra with the Karasev-Novikova quadratic commutation relations. The representations
are associated with resonance spectral clusters near the energy level of the unperturbed hydrogen atom. We find
asymptotics for a series of eigenvalues and corresponding asymptotic eigenfunctions near the ...
Added: December 7, 2020
Springer, 2020.
This edited volume gathers selected, peer-reviewed contributions presented at the fourth International Conference on Differential & Difference Equations Applications (ICDDEA), which was held in Lisbon, Portugal, in July 2019.
First organized in 2011, the ICDDEA conferences bring together mathematicians from various countries in order to promote cooperation in the field, with a particular focus on applications. ...
Added: November 1, 2020
Vakhrameeva D. A., Pereskokov A. V., Journal of Mathematical Sciences 2020 Vol. 247 No. 6 P. 820–849
We study the spectral problem for a two-dimensional Hartree type operator with smooth selfaction potential. We find
asymptotic eigenvalues and eigenfunctions and construct an asymptotic expansion for quantum averages near
the lower boundaries of spectral clusters. ...
Added: June 22, 2020
Синцова К. А., Лялинов М. А., Wave Motion, 2018.
In this work we construct and discuss special solutions of a homogeneous problem for the Laplace
equation in a domain with the cone-shaped boundaries. The problem at hand is interpreted as that
describing oscillatory linear wave movement of a uid under gravity in such a domain. These solutions are found in terms of the Mellin transform and ...
Added: November 27, 2019