### ?

## Real or Imaginary? (On pair creation in de Sitter space)

Modern Physics Letters A. 2010. Vol. 25. No. 33. P. 2815-2823.

Akhmedov E.

Akhmedov E., Бурда Ф., physical review D 2012 Vol. 86

We propose an ansatz which solves the Dyson-Schwinger equation for the real scalar fields in Poincare patch of de Sitter space in the IR limit. The Dyson-Schwinger equation for this ansatz reduces to the kinetic equation, if one considers scalar fields from the principal series. Solving the latter equation we show that under the adiabatic ...

Added: February 17, 2013

Akhmedov E., Journal of High Energy Physics 2012 Vol. 1201 P. 066

We explicitly show that the one loop IR correction to the two--point function in de Sitter space scalar QFT does not reduce just to the mass renormalization. The proper interpretation of the loop corrections is via particle creation revealing itself through the generation of the quantum averages $<a^+_p a_p>$, $<a_p a_{-p}>$ and $<a^+_p a^+_{-p}>$, which ...

Added: February 17, 2013

Akhmedov E., International Journal of Modern Physics D 2014 Vol. 23 No. 1 P. 1430001

We discuss peculiarities of quantum fields in de Sitter space on the example of the self-interacting massive real scalar, minimally coupled to the gravity background. Non-conformal quantum field theories in de Sitter space show very special infrared behavior, which is not shared by quantum fields neither in flat nor in anti-de-Sitter space: in de Sitter ...

Added: October 31, 2013

Akhmedov E., Physical Review D - Particles, Fields, Gravitation and Cosmology 2013 Vol. 87 No. 4 P. 044049

Following Krotov and Polyakov [ Nucl. Phys. B849 410 (2011)], we show that in global de Sitter space its isometry is broken by the loop IR divergences for any invariant vacuum state of the massive scalars. We derive a kinetic equation in global de Sitter space that follows from the Dyson-Schwinger equation of the Schwinger-Keldysh ...

Added: February 27, 2013

Akhmedov E., Буйвидович П., Синглетон Д., Physics of Atomic Nuclei 2012 Vol. 75 P. 525-529

We give general arguments that any interacting non--conformal {\it classical} field theory in de Sitter space leads to the possibility of constructing a perpetuum mobile. The arguments are based on the observation that massive free falling particles can radiate other massive particles on the classical level as seen by the free falling observer. The intensity ...

Added: February 17, 2013

Akhmedov E., Федор П., Слепухин В., Physical Review D - Particles, Fields, Gravitation and Cosmology 2013 Vol. 88 No. 2 P. 024021

We study massive real scalar $\phi^4$ theory in the expanding Poincare patch of de Sitter space. We calculate the leading two-loop infrared contribution to the two-point function in this theory. We do that for the massive fields both from the principal and complementary series. As can be expected at this order light fields from the ...

Added: August 31, 2013

Slunyaev A., Кокорина А. В., 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

Pelinovsky E., Didenkulova I., Rybkin A., 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

Pelinovsky E., Kurkin A. A., Kozelkov A. 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

Bodrova A., Osinsky A., Brilliantov N. V., Scientific Reports 2020 Vol. 10 No. 693 P. 1-15

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

Праздничных А. И., Glazov M., Ren L. 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

Marshakov A., Миронов А. Д., Морозов А. Ю., 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

Semenov A. G., Zaikin A. D., 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

Окубо Ю. undefined., 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

Semenov-Tian-Shansky K., Поляков М., Смирнов А. 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

Maslov V., 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

Семин С. В., Kurkina O. E., Kurkin A. A. 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

Musaev E., Berman D. S., Thompson D. C., 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

Akhmedov E., Musaev E., 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

Min N., Younghun K., 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

Budkov Y., Kolesnikov A., 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

Zhukov A., Shapiro D., Pogosov W. et al., Physical Review B: Condensed Matter and Materials Physics 2016 Vol. 93 P. 063845

Superconducting circuits provide a new platform for study of nonstationary cavity QED phenomena. An example of such a phenomenon is the dynamical Lamb effect, which is the parametric excitation of an atom due to nonadiabatic modulation of its Lamb shift. This effect was initially introduced for a natural atom in a varying cavity, while we ...

Added: October 18, 2016

Kolokolov I., Lebedev V., Chertkov M. 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