Drift of domain walls in a harmonic magnetic field

It is shown that a two-step form of the dynamic magnetization curve (and the hysteresis loop) established for a multiaxial ferrite-garnet wafer with a low quality factor (Q < 1) and considerable anisotropy in the plane (K p /K u = 14) in the frequency range of 25-1000 Hz is explained by the reconstruction of the dynamic domain structure, particularly by the established features of the drift of domain boundaries in the harmonic magnetic field. © 2013 Allerton Press, Inc

Casimir Energy of the Universe and the Dark Energy Problem

We regard the Casimir energy of the universe as the main contribution to the cosmological constant. Using 5 dimensional models of the universe, the flat model and the warped one, we calculate Casimir energy. Introducing the new regularization, called {\it sphere lattice regularization}, we solve the divergence problem. The regularization utilizes the closed-string configuration. We consider 4 different approaches: 1) restriction of the integral region (Randall-Schwartz), 2) method of 1) using the minimal area surfaces, 3) introducing the weight function, 4) {\it generalized path-integral}. We claim the 5 dimensional field theories are quantized properly and all divergences are renormalized. At present, it is explicitly demonstrated in the numerical way, not in the analytical way. The renormalization-group function (\be-function) is explicitly obtained. The renormalization-group flow of the cosmological constant is concretely obtained.Comment: 12 pages, 13 figures, Proceedings of DSU2011(2011.9.26-30,Beijin

Motion and Interaction of Magnetic Dislocations in Alternating Magnetic Field

Abstract The behavior of magnetic dislocations (MDs) in an alternating harmonic magnetic field in iron garnets has been experimentally investigated. The results are presented for single-crystal plates in which the drift of domain walls is observed in fields of sound frequencies. It is found that MDs in a stripe domain structure are able to move not only along but also across domain walls. A pairwise interaction between magnetic dislocations when they approach each other to distances on the order of the sizes of the cores of MDs is revealed. The processes of the annihilation, mutual passing of magnetic dislocations through each other and overtaking are found. The features of the dynamic behavior of MDs are explained using a mechanism based on the presence of vertical Bloch lines in a structure of domain walls. MDs are formed at nucleation centers, and their nucleation field is lower than the drift-starting field, which corresponds to previously proposed dislocational mechanism of the drift. The dependencies of quantitative parameters of the drift and MDs on amplitude and frequency of the pumping field are determined. The behavior of MDs should be considered when analyzing the mechanisms for magnetization and temperature-dependent phase transitions in magnetic layers

Experimental and Theoretical Study of Stripe Magnetic Domain Structure Drift in Iron Garnet Crystals

The results of experimental and theoretical study of magnetic domain structure drift in low frequency oscillating magnetic field oriented perpendicular to the sample plate are presented. Experimental study was performed on uniaxial iron garnet (TbErGd)₃(FeAl)₅O₁₂ (111) plate with rhombic anisotropy for the case when orientation of domain walls of stripe domains is preserved. Dynamic domain structure was revealed by means of magnetooptic Faraday effect and registered by high speed digital camera at the speed equal to 1200 fps. Theoretical model based on the motion equations for coupled harmonic oscillators that takes into account attenuation and field inhomogeneity along the plate is proposed

Unidirectional motion of magnetic domain walls: The experiment and numerical simulation

The results of study of unidirectional motion of topologically different domain structures under the influence of periodic bipolar and unipolar magnetic field pulses applied perpendicular to the sample plane of (111) iron garnet single crystal plate are presented. The response of the domain structure to the field pulses was studied by direct observations utilizing the stroboscopic technique. Experimentally obtained dependences of the speed of unidirectional motion of stripe domains on the parameters of external bipolar pulsed magnetic field are compared with the results of numerical simulations. © Published under licence by IOP Publishing Ltd.Ministry of Science and Higher Education of the Russian Federation: 3.6121.2017The work was performed within the framework of the basic part of the state assignment of the Ministry of Science and Higher Education of the Russian Federation (project 3.6121.2017)

Deconstructing holographic liquids

We argue that there exist simple effective field theories describing the long-distance dynamics of holographic liquids. The degrees of freedom responsible for the transport of charge and energy-momentum are Goldstone modes. These modes are coupled to a strongly coupled infrared sector through emergent gauge and gravitational fields. The IR degrees of freedom are described holographically by the near-horizon part of the metric, while the Goldstone bosons are described by a field-theoretical Lagrangian. In the cases where the holographic dual involves a black hole, this picture allows for a direct connection between the holographic prescription where currents live on the boundary, and the membrane paradigm where currents live on the horizon. The zero-temperature sound mode in the D3-D7 system is also re-analyzed and re-interpreted within this formalism.Comment: 21 pages, 2 figure

Wilsonian Approach to Fluid/Gravity Duality

The problem of gravitational fluctuations confined inside a finite cutoff at radius $r=r_c$ outside the horizon in a general class of black hole geometries is considered. Consistent boundary conditions at both the cutoff surface and the horizon are found and the resulting modes analyzed. For general cutoff $r_c$ the dispersion relation is shown at long wavelengths to be that of a linearized Navier-Stokes fluid living on the cutoff surface. A cutoff-dependent line-integral formula for the diffusion constant $D(r_c)$ is derived. The dependence on $r_c$ is interpreted as renormalization group (RG) flow in the fluid. Taking the cutoff to infinity in an asymptotically AdS context, the formula for $D(\infty)$ reproduces as a special case well-known results derived using AdS/CFT. Taking the cutoff to the horizon, the effective speed of sound goes to infinity, the fluid becomes incompressible and the Navier-Stokes dispersion relation becomes exact. The resulting universal formula for the diffusion constant $D(horizon)$ reproduces old results from the membrane paradigm. Hence the old membrane paradigm results and new AdS/CFT results are related by RG flow. RG flow-invariance of the viscosity to entropy ratio $\eta /s$ is shown to follow from the first law of thermodynamics together with isentropy of radial evolution in classical gravity. The ratio is expected to run when quantum gravitational corrections are included.Comment: 34 pages, harvmac, clarified boundary conditio

Non-intersecting squared Bessel paths and multiple orthogonal polynomials for modified Bessel weights

We study a model of $n$ non-intersecting squared Bessel processes in the confluent case: all paths start at time $t = 0$ at the same positive value $x = a$, remain positive, and are conditioned to end at time $t = T$ at $x = 0$. In the limit $n \to \infty$, after appropriate rescaling, the paths fill out a region in the $tx$-plane that we describe explicitly. In particular, the paths initially stay away from the hard edge at $x = 0$, but at a certain critical time $t^*$ the smallest paths hit the hard edge and from then on are stuck to it. For $t \neq t^*$ we obtain the usual scaling limits from random matrix theory, namely the sine, Airy, and Bessel kernels. A key fact is that the positions of the paths at any time $t$ constitute a multiple orthogonal polynomial ensemble, corresponding to a system of two modified Bessel-type weights. As a consequence, there is a $3 \times 3$ matrix valued Riemann-Hilbert problem characterizing this model, that we analyze in the large $n$ limit using the Deift-Zhou steepest descent method. There are some novel ingredients in the Riemann-Hilbert analysis that are of independent interest.Comment: 59 pages, 11 figure

Принципиальное значение запрета на поворот к худшему для уголовно-процессуальной системы

The article deals with the problem of the expediency of a criminal case’s returning to the prosecutor at the stage of appointment and preparation of a court session in Russian criminal proceedings. This problem is relevant to the science of criminal procedure.The purpose of the study is to analyze critically the practice of returning of a criminal case back to the prosecutor in order to correct mistakes made at the pre-trial stages of the proceedings according to the new concept of justice independence and the absence of an accusatory bias in the court functioning.The methodological basis of the study is a set of scientific techniques, focused mostly on the dialectical approach, which made it possible to determine the essential characteristics of the prohibition to turn the criminal proceedings in Russia for the worse. Both general scientific (analysis, synthesis, systematic method) and specific scientific methods (formal-legal, historical-legal, comparative-legal) of knowledge were also used. The analysis helped to formulate the position of understanding the turn for the worse as an independent principle of criminal procedural law, to study the procedural form of the turn for the worse. The synthesis method made it possible to determine the return of the criminal case to the prosecutor at the stage of appointment and preparation of the court session as a holistic institution of the criminal procedure. The systematic approach allowed to determine not only the mixed nature of the mechanism for changing the prosecution to a more serious one, but the investigative organization of pre-trial proceedings and its place in the structure of criminal proceedings, the separation of the investigative and “accusatory powers” of the prosecutors as well as their balance. The historical method let us trace the evolution of the prohibition to turn the Soviet and Russian criminal procedural systems for the worse. The comparative-legal method made it possible to assess the potential of domestic legislators' reception of foreign experience of regulating the prohibition to turn for the worse and formulate proposals to improve the Russian criminal procedural legislation.The main scientific results of this research consist of justification of the conclusion of the conversion expediency of the domestic judicial proceedings to the adversarial model of accusation which is carried out within the trial on the previously filed charge. The presentation of a new charge (criminal action) in court and the procedure of supplementing the charge change it for the worse. This model of re-indictment for the worse for the defendant appears to be fairer and more convenient both for the prosecuting authority and for the legal organization of combating crime. The changeover to the suggested form of implementation of the ban to turn for the worse in the institution of bringing and changing charges in court is possible only in a systematic link with the reform of the preliminary investigation. Conclusion. The institution of the criminal case returning by the court to the prosecutor in order to change the charge to a more serious one when implementing the adversarial model of bringing charges in the criminal procedure system of Russia will fully satisfy the concept of independence of justice administration and the absence of an accusatory bias in the activities of the court, while at the same time with fairly organized the prosecutorial power aimed at countering crime.The section 1 was prepared by N.N. Lysov, section 2 by K.D. Vanyan (together with M.T. Tashilin), section 3 by A.S. Shuisky (together with I.R. Gilmanov), section 4 by V.V. Kosterin.Исследование посвящено актуальной для уголовно-процессуальной науки проблеме целесообразности существования в российском уголовном судопроизводстве института возвращения прокурору уголовного дела на стадии назначения и подготовки судебного заседания. По мнению авторов, запрет на поворот к худшему имеет более фундаментальное значение для уголовно-процессуальной системы, чем ему обычно приписывает теория. Справедливость и эффективность процедуры возвращения судом дела на доследование, позволяющей следователю изменить положение подсудимого посредством предъявления нового обвинения, сомнительны. Предпочтительнее выглядит модель изменения государственным обвинителем обвинения в суде с соблюдением состязательной процедуры, существующая в ряде государств, имеющих состязательный тип уголовного судопроизводства.Раздел 1 подготовлен Н.Н. Лысовым, раздел 2 – К.Д. Ванян (совместно с М.Т. Тащилиным ), раздел 3 – А.С. Шуйским (совместно с И.Р. Гильмановым), раздел 4 – В.В. Костериным