Обобщенный метод стационарной фазы для преобразования Фурье быстроосциллирующей функции
Mathematical notes. 2017. Т. 102. № 6. С. 816-827.
Grushin V. V.
Asymptotic formulas are obtained for a class of integrals that are Fourier transforms of rapidly oscillating functions. These formulas contain special functions and generalize the well-known method of stationary phase.
Research target: Mathematics
Priority areas: mathematics
, Математические заметки 2016
Added: December 13, 2016
, Sbornik Mathematics 2012 Vol. 203 No. 11 P. 1647-1653
We consider the Paley--Wiener spaces of L2-functions whose Fourier transform has a bounded support. We show that every continuous mapping that generates a superposition operator acting on these spaces is affine and injective. ...
Added: January 29, 2013
Асимптотическое поведение собственных значений оператора Шредингера в тонких бесконечных и тонких замкнутых трубках
, Наноструктуры. Математическая физика и моделирование 2012 Т. 7 № 2 С. 17-44
В работе получено асимптотическое разложение собственных значений оператора Лапласа с нулевыми данными Дирихле в бесконечных трубках, т. е. в бесконечных изогнутых цилиндрах с внутренним кручением при равномерном сжатии поперечных сечений, по малому параметру, характеризующему поперечные размеры трубки. Аналогичное разложение получено для оператора Шредингера с учетом магнитного поля для конечных изогнутых трубок. Предложен метод сведения задачи ...
Added: December 24, 2012
Application of the Generalized Stationary Phase Method to the Asymptotics of the Tsunami Head Wave in the Hydrodynamic Piston Model
, Russian Journal of Mathematical Physics 2019 Vol. 26 No. 3 P. 344-351
Formulas for the asymptotics of some class of integrals of rapidly oscillating functions that generalize the well-known stationary phase method, which were obtained in the previous paper of the author, are applied to integrals arising in the well-known tsunami hydrodynamic piston model in the case of a constant pool bottom. As a result, asymptotic formulas ...
Added: October 14, 2019
, Mathematics of Computation 2017 Vol. 86 No. 305 P. 1499-1524
For an arbitrary set of nonnegative integers, we consider the Euler binary partition function which equals the total number of binary expansions of an integer with ``digits'' from . By applying the theory of subdivision schemes and refinement equations, the asymptotic behaviour of as is characterized. For all finite , we compute the lower and upper exponents of growth of , find when ...
Added: May 11, 2017
, , Russian Journal of Mathematical Physics 2019 Vol. 26 No. 3 P. 334-343
The problem of viscous compressible fluid flow in an axially symmetric pipe with small periodic irregularities on the wall is considered for large Reynolds numbers. An asymptotic solution with double-deck structure of the boundary layer and unperturbed core flow is obtained. Numerical investigations of the influence of the density of the core flow on the flow behavior in ...
Added: September 2, 2019
, , Вестник Московского государственного строительного университета 2014 № 7 С. 34-40
A classic pursuit problem is studied in which two material points - a Pursuer and a Pursued - move in a plane at constant speeds. The velocity vector of the Pursued does not change its direction and the velocity vector of the Pursuer turns and always aims at the Pursued. If the Pursuer moves at ...
Added: August 3, 2014
, Discrete and Continuous Dynamical Systems 2013 Vol. 33 No. 1 P. 239-254
We present an approach to study degenerate ODE with periodic nonlinearities; for resonant higher order nonlinear equations L(p)x=f(x)+b(t), p=d/dt, with 2pi-periodic forcing b and periodic f we give multiplicity results, in particular, conditions of existence of infinite and unbounded sets of 2pi-periodic solutions. ...
Added: February 11, 2013
, Discrete and Continuous Dynamical Systems - Series S 2013 Vol. 6 No. 4 P. 999-1016
Autonomous higher order differential equations with scalar nonlinearities, periodic with respect to the main phase variable under appropriate generic conditions, have an infinite sequence of isolated cycles with amplitudes growing to infinity and periods converging to some specific value T. ...
Added: February 11, 2013
, , Mathematische Nachrichten 2020 Vol. 293 P. 210-225
We consider fourth order ordinary differential operators on the half-line and on the line, where the perturbation has compactly supported coefficients. The Fredholm determinant for this operator is an analytic function in the whole complex plane without zero.We describe the determinant at zero.We show that in the generic case it has a pole of order 4 in the case ...
Added: February 5, 2021
, , , International Journal for Computational Civil and Structural Engineering 2018 Vol. 14 No. 1 P. 92-101
The filtration problem in a porous medium is an important part of underground hydromechanics. Filtration of suspensions and colloids determines the processes of strengthening the soil and creating waterproof walls in the ground while building the foundations of buildings and underground structures. It is assumed that the formation of a deposit is dominated by the ...
Added: July 1, 2018
, , International Journal for Computational Civil and Structural Engineering 2017 Т. 13 № 1 С. 63-68
Filtration of the suspension in a porous medium with a geometric particle capture mechanism is considered. The porous medium has an initial deposit unevenly distributed across the filter. The nonlinear model of deep bed filtration suggests that the porosity and permeability of the porous medium depend on the deposit. The asymptotics of the movable boundary ...
Added: January 6, 2018
, , Теория вероятностей и ее применения 2004 Т. 49 № 2 С. 352-362
Показано, что σ-конечная борелевская мера на положительной полупрямой с невозрастающей плотностью (относительно меры Лебега) однозначно характеризуется своей симметризацией. ...
Added: October 7, 2013
Double-deck structure in the fluid flow problem over plate with small irregularities of time-dependent shape
, European Journal of Mechanics - B/Fluids 2021 Vol. 89 P. 401-410
An asymptotic solution with double-deck boundary layer structure is constructed for the problem of an incompressible fluid flow along a semi-infinite plate with small localized or periodic (fast-oscillating) irregularities on the surface whose shape depends on time. Numerical simulation of flow in the near-plate region is presented for two types of the shape change: oscillations of the ...
Added: January 4, 2021
, Математические заметки 2014 Т. 95 № 5 С. 775-789
The paper deals with solutions to Emden-Fowler-type equations of any arbitrary order. The asymptotic properties of solutions to these equations are studied, and a systematic surveyof numerous uncoordinated results of analysis of continuable and noncontinuable solutions is given. ...
Added: April 4, 2014
On the asymptotics of the element counting function in an additive arithmetic semigroup with exponential counting function of prime generators
, , , Functional Analysis and Its Applications 2016 Vol. 50 No. 4 P. 291-307
We find the asymptotics of the element counting function for an additive arithmetic semigroup with exponential growth of the counting function of prime generators. ...
Added: October 18, 2015
Nonstationary double-deck structure of boundary layers in compressible flow problem inside a channel with small irregularities on the walls
, , Russian Journal of Mathematical Physics 2021 Vol. 28 No. 2 P. 224-243
A subsonic flow of a viscous compressible fluid in a two-dimensional channel with small periodic or localized irregularities on the walls for large Reynolds numbers is considered. A formal asymptotic solution with double-deck structure of the boundary layer is constructed. A nontrivial time hierarchy is discovered in the decks. An analysis of the scales of irregularities at ...
Added: March 22, 2021
, , Математический сборник 2020 Т. 211 № 1 С. 125-174
In this work we construct a harmonic analysis on free Abelian groups of rank 2, namely: we construct and investigate spaces of functions and distributions, Fourier transforms and actions of discrete and extended discrete Heisenberg groups. In the case of the rank-2 value group of a two-dimensional local field with finite last residue field we ...
Added: May 20, 2020
, Asymptotic Analysis 2019 Vol. 115 P. 223-239
The Riccaty equation with coefficients having power asymptotic in a neighbourhood of infinity is studied. We examine the solutions to these equations and describe their asymptotic form ...
Added: November 24, 2019
, Математический сборник 2012 Т. 203 № 11 С. 121-128
We consider the Paley--Wiener spaces of L2 -functions whose Fourier transform has a bounded support. We show that every continuous mapping that generates a superposition operator acting on these spaces is affine and injective. ...
Added: February 13, 2013
, Mathematical notes 1994 Vol. 56 No. 2 P. 132-136
Added: September 23, 2016
, , Russian Journal of Mathematical Physics 2011 Vol. 18 No. 1 P. 10-25
The goal in this paper is to demonstrate a new method for constructing global-in-time approximate (asymptotic) solutions of (pseudodifferential) parabolic equations with a small parameter. We show that, in the leading term, such a solution can be constructed by using characteristics, more precisely, by using solutions of the corresponding Hamiltonian system and without using any ...
Added: April 12, 2012
, , , Промышленное и гражданское строительство 2020 № 6 С. 64-68
Filtration problem for a suspension in a porous medium characterize the injection of a liquid grout into porous rock to strengthen loose soil or create waterproof partitions during the construction of tunnels and underground structures. The suspension is injected under pressure into an empty homogeneous porous medium and moves from inlet to outlet. Some particles ...
Added: July 2, 2020
, , Вестник Московского государственного строительного университета 2017 No. 11 P. 1278-1283
Subject: a groundwater filtration affects the strength and stability of underground and hydro-technical constructions. Research objectives: the study of one-dimensional problem of displacement of suspension by the flow of pure water in a porous medium. Materials and methods: when filtering a suspension some particles pass through the porous medium, and some of them are stuck ...
Added: January 6, 2018