Activation instanton in real-time formalism
Modern Physics Letters A. 2014. Vol. 28. No. 16. P. 1450128-1-1450128-7.
I.V. Kolokolov, Nguyen Thanh T.
In this paper, we study the dynamics of the activation of a Brownian particle using the path integral formalism in real time. Along with the construction of the saddle-point (instanton) solutions, we develop the formalism allowing to calculate the effect of the fluctuations near this solution in detail. In particular, it is shown that there is a soft mode for which the integration is not Gaussian and just this mode is responsible for the finite probability flux.
Research target: Physics
Priority areas: mathematics
, , Physical Review B 2007 № 75 С. 140201-1-140201-4
A modification of the optimal fluctuation approach is applied to study the tails of the free-energy distribution function PLF for an elastic string in quenched disorder both in the regions of the universal behavior of PLF and in the regions of large fluctuations, where the behavior of PLF is nonuniversal. The difference between the two regimes is shown ...
Added: February 10, 2017
Universal and non-universal tails of distribution functions in the directed polymer and Kardar-Parisi-Zhang problem.
, , Physical Review B: Condensed Matter and Materials Physics 2008 Vol. 78 P. 024206-1-024206-16
The optimal-fluctuation approach is applied to study the most distant nonuniversal tails of the free-energy distribution function PLF for an elastic string of a large but finite length L interacting with a quenched random potential. A further modification of this approach is proposed which takes into account the renormalization effects and allows one to study the closest universal ...
Added: February 10, 2017
Long-range interactions between membrane inclusions: Electric field induced giant amplification of the pairwise potential
, , et al., Annals of Physics, Elsevier 2022 Vol. 447 No. 2 Article 168916
The aim of this work is to revisit the phenomenological theory of the interaction between membrane inclusions, mediated by the membrane fluctuations. We consider the case where the inclusions are separated by distances larger than their characteristic size. Within our macroscopic approach a physical nature of such inclusions is not essential, however we have always in ...
Added: October 28, 2022
Studying the specific features of free rise of solid spheres in a viscous fluids at moderate Reynolds numbers
, , et al., European Journal of Mechanics - B/Fluids 2018 Vol. 72 P. 616-623
The paper presents results of numerical simulations of freely rising solid spheres in a viscous fluid. The diameter of spheres was 5 mm, 7 mm, 10 mm, and 20 mm, and the corresponding Reynolds numbers varies in the interval 1400 < Re < 10100. It has been found that the free rise path varies, as the Galileo number ...
Added: October 21, 2018
Nonlinear wave run-up in bays of arbitrary cross-section: generalization of the Carrier-Greenspan approach
, , , Journal of Fluid Mechanics 2014 Vol. 748 P. 416-432
We present an exact analytical solution of the nonlinear shallow water theory for wave run-up in inclined channels of arbitrary cross-section, which generalizes previous studies on wave run-up for a plane beach and channels of parabolic cross-section. The solution is found using a hodograph-type transform, which extends the well-known Carrier–Greenspan transform for wave run-up on ...
Added: November 19, 2014
Account of occasional wave breaking in numerical simulations of irregular water waves in the focus of the rogue wave problem
, , Water Waves, Springer 2019 P. 1-20
The issue of accounting of the wave breaking phenomenon in direct numerical simulations of oceanic waves is discussed. It is emphasized that this problem is crucial for the deterministic description of waves, and also for the dynamical calculation of extreme wave statistical characteristics, such as rogue wave height probability, asymmetry, etc. The conditions for accurate ...
Added: October 13, 2019
, , , Нелинейная динамика 2017 Т. 13 № 3 С. 399-412
В статье, используя методы теории динамических систем Морса–Смейла, авторы рассматривают топологическую структуру для точечно-зарядной модели магнитного поля областей фотосферы. Для произвольного количества зарядов (безотносительно к их местоположению) и не предполагая потенциальности поля <span data-mathml="B⃗ (следовательно, не используя конкретных формул), авторы приводят оценки, связывающие количества зарядов определенного типа с количеством нуль-точек. Для граничных оценок описывается топологическая структура магнитного ...
Added: October 12, 2017
, , et al., Journal of Lightwave Technology 2004 Vol. 22 No. 4 P. 1155-1168
This paper presents a method that allows evaluating the performance of an optical fiber system where bit errors result from a complex interplay of spontaneous noise generated in optical amplifiers and birefringent disorder of the transmission fiber. We demonstrate that in the presence of temporal fluctuations of birefringence characteristics, the bit-error rate (BER) itself is ...
Added: February 23, 2017
, , et al., Теоретическая и математическая физика 2019 Т. 200 № 2 С. 290-309
Leading logarithms in massless nonrenormalizable effective field theories can be computed using nonlinear recurrence relations. These recurrence relations follow from the fundamental requirements of unitarity, analyticity, and crossing symmetry of scattering amplitudes and generalize the renormalization group technique to the case of nonrenormalizable effective field theories. We review the existing exact solutions of nonlinear recurrence relations relevant for field ...
Added: September 29, 2020
М. : ИКИ РАН, 2011
Added: March 26, 2013
Control of the exciton valley dynamics in atomically thin semiconductors by tailoring the environment
, , et al., Physical Review B: Condensed Matter and Materials Physics 2021 Vol. 103 No. 8 P. 085302-1-085302-12
The exciton valley dynamics in van der Waals heterostructures with transition metal dichalcogenide monolayers is driven by the long-range exchange interaction between the electron and the hole in the exciton. It couples the states active in the opposite circular polarizations resulting in the longitudinal-transverse splitting of excitons propagating in the monolayer plane. Here we study ...
Added: March 5, 2021
, , , Journal of Geometry and Physics 2011 Vol. 61 P. 1203-1222
We present a summary of current knowledge about the AGT relations for conformal blocks with additional insertion of the simplest degenerate operator, and a special choice of the corresponding intermediate dimension, when the conformal blocks satisfy hypergeometric-type differential equations in position of the degenerate operator. A special attention is devoted to representation of conformal block ...
Added: February 28, 2013
, , Physical Review B: Condensed Matter and Materials Physics 2013 Vol. 88 No. 5 P. 054505-1-054505-10
We investigate the effect of interacting quantum phase slips on persistent current and its fluctuations in ultrathin superconducting nanowires and nanorings pierced by the external magnetic flux. We derive the effective action for these systems and map the original problem onto an effective sine-Gordon theory on torus. We evaluate both the flux dependent persistent current ...
Added: February 9, 2015
, Journal of Physics: Conference Series 2017 Vol. 804 No. 012036 P. 1-8
We investigate the existence and the orthogonality of the generalized Jack symmetric functions which play an important role in the AGT relations. We show their orthogonality by deforming them to the generalized Macdonald symmetric functions. ...
Added: October 26, 2017
, Russian Journal of Mathematical Physics 2019 Vol. 26 No. 2 P. 168-173
The parameters of unstable short-living isotopes are studied from the mathematical point of view. The values of the chemical potential and activity parameters that determine the neutron halo arising when the neutron separates from the nucleus of an unstable isotope are calculated. The analogy between nuclear physics and economics is considered from the point of view of such parameters as ...
Added: August 25, 2019
, Applied Mathematics 2010 Vol. 1 P. 1-7
Added: October 5, 2019
, Теоретическая и математическая физика 2019 Т. 201 № 1 С. 65-83
We study the process of a nucleon separating from an atomic nucleus from the mathematical standpoint using experimental values of the binding energy for the nucleus of the given substance. A nucleon becomes a boson at the instant of separating from a fermionic nucleus. We study the further transformations of boson and fermion states of separation in a ...
Added: November 1, 2019
, , et al., Труды НГТУ им. Р.Е. Алексеева 2012 № 2(95) С. 48-65
Purpose: Numerical modeling of internal baroclinic disturbances of different shapes in a model lake with variable depth, analysis of velocity field of wave-induced current, especially in the near-bed layer. Approach: The study is carried out with the use of numerical full nonlinear nonhydrostatic model for stratified fluid. Findings: The full nonlinear numerical modeling of internal wave dynamics ...
Added: October 6, 2012
, , , Journal of High Energy Physics 2012 Vol. 1210
The reduction of the duality invariant approach to M-theory by a U-duality group valued Scherk-Schwarz twist is considered. We show that all gaugings of SUGRA can be obtained by dimensional reduction of the extended space. ...
Added: October 20, 2014
, , Physical Review D - Particles, Fields, Gravitation and Cosmology 2010 Vol. 81 P. 085010
We show that Polchinski equations in the D-dimensional matrix scalar field theory can be reduced at large N to the Hamiltonian equations in a (D+1)-dimensional theory. In the subsector of the Trϕl (for all l) operators we find the exact form of the corresponding Hamiltonian. The relation to the holographic renormalization group is discussed. ...
Added: February 27, 2013
, , Polymer Science - Series C 2018 Vol. 60 No. Supplement 1 P. 148-159
Theoretical models of the conformational behavior of flexible polymer chains in mixed solvents enunciated in the world literature during the last decade are critically reviewed. Models describing different mechanisms of coil-to-globule transitions in a good solvent induced by cosolvent addition are highlighted. Special attention is given to the analysis of theoretical approaches to describing the ...
Added: November 30, 2018
Temperature distribution in driven granular mixtures does not depend on mechanism of energy dissipation
, , , Scientific Reports 2020 Vol. 10 Article 693
We study analytically and numerically the distribution of granular temperatures in granular mixtures for different dissipation mechanisms of inelastic inter-particle collisions. Both driven and force-free systems are analyzed. We demonstrate that the simplified model of a constant restitution coefficient fails to predict even qualitatively a granular temperature distribution in a homogeneous cooling state. At the same time we reveal ...
Added: February 25, 2020
, , Scientific Reports 2018 Vol. 8 No. 1 P. 16915-1-16915-18
Sequential state discrimination is a strategy for quantum state discrimination of a sender’s quantum states when N receivers are separately located. In this report, we propose optical designs that can perform sequential state discrimination of two coherent states. For this purpose, we consider not only binary phase-shifting-key (BPSK) signals but also general coherent states, with arbitrary prior probabilities. Since ...
Added: November 16, 2020
, , , Journal of Experimental and Theoretical Physics 2011 Vol. 140 No. 2 P. 387-400
We analyze magnetic kinematic dynamo in a conducting fluid where the stationary shear flow is accompanied by relatively weak random velocity fluctuations. The diffusionless and diffusion regimes are described. The growth rates of the magnetic field moments are related to the statistical characteristics of the flow describing divergence of the Lagrangian trajectories. The magnetic field ...
Added: February 2, 2017