Spatio-temporal structure of Cherenkov radiation excited by a laser pulse in an ionic dielectric waveguide

The process of excitation of Cherenkov electromagnetic radiation by a laser pulse in an ionic dielectric waveguide, is investigated. The frequency spectrum and mode composition of the Cherenkov radiation are determined. The spatio-temporal structure of the Cherenkov electromagnetic field is obtained and investigated.Досліджено процес збудження черенковського електромагнітного випромінювання лазерним імпульсом в іонному діелектричному хвилеводі. Визначено частотний спектр та модовий склад черенковського випромінювання. Отримана й досліджена просторово-часова структура черенковського електромагнітного поля.Исследован процесс возбуждения черенковского электромагнитного излучения лазерным импульсом в ионном диэлектрическом волноводе. Определены частотный спектр и модовый состав черенковского излучения. Полученa и исследована пространственно-временная структура черенковского электромагнитного поля

Interregional Inequality of Population Incomes: Problems of Methodology and Estimation in the Russian Federation

Currently, the priority of the Russian Federation socio-economic development is to achieve sustainable economic growth. A significant obstacle to the achievement of this goal is the unevenness and disproportionality in the socio-economic development of the Russian regions. This circumstance makes the problem of an objective and adequate assessment of Russian regions the interregional differentiation particularly relevant. The study notes that the nominal monetary income of the population does not take into account regional differences in price level. This work discusses methodological approaches of reliable determination, advantages of weighted and unweighted estimates in the interregional inequality, special attention is paid to weighing the average per capita indicators of the subject of the Russia for the proportion of the region’s population in the country’s population. To assess the purchasing power of the population at the regional level, the authors propose to use a modified cost of living index. As a result of the study, the dynamics of the variation coefficient of the average per capita monetary incomes of the population and adjusted for the modified cost-of-living index were determined, on the basis of which the regions of Russia were divided into three groups. The efficiency of the transition to the analysis of incomes comparable in purchasing power, as comparison of weighted and unweighted variation coefficients, has been proved. The trend towards smoothing interregional inequality, which is caused by the accelerated growth of real incomes of the population in the low-income group of Russian regions

Hawking radiation of nonsingular black holes in two dimensions

In this letter we study the process of Hawking radiation of a black hole assuming the existence of a limiting physical curvature scale. The particular model is constructed using the Limiting Curvature Hypothesis (LCH) and in the context of two-dimensional dilaton gravity. The black hole solution exhibits properties of the standard Schwarzschild solution at large values of the radial coordinate. However, near the center, the black hole is nonsingular and the metric becomes that of de Sitter spacetime. The Hawking temperature is calculated using the method of complex paths. We find that such black holes radiate eternally and never completely evaporate. The final state is an eternally radiating relic, near the fundamental scale, which should make a viable dark matter candidate. We briefly comment on the black hole information loss problem and the production of such black holes in collider experiments.Comment: 8 pages, 4 figures; minor revisions; references added; version to appear in JHE

Study of wakefields in longitudinally and transversely inhomogeneous rectangular dielectric resonators

At Institute of Plasma Electronics and New Methods of the Acceleration of NSC KIPT the experimental inspection of the principles of creation of multi-bunch and the multimode wakefield dielectric accelerator is carried out. For clearing up of the physical processes arising in case of excitation the wakefield and dynamics of electron bunches in such accelerator we executed a series of analytical and numerical calculations, and also full three-dimensional simulation by means of the developed 3D code is carried out. Wakefields were excited in case of injection of sequence of electron bunches in a rectangular vacuum wave guide of R32 type (72.14 ×34.04 mm) or R26 type (86.36 ×43.18 mm), filled with dielectric with the relative dielectric permittivity ε = 3.8, covering two opposite wide walls of a waveguide. The bunch repetition frequency was 2,805 GHz, energy of electrons was 4.5 MeV, average current was 0.73 A and a charge of one bunch was 0.26 nC. The electron bunches arriving through an open input end of a dielectric waveguide were deviated by a cross magnetic field of permanent magnets to a metal wall of waveguide free of dielectric. Depending on the location of magnets along a structure axis the length of interaction of electron bunches with a dielectric waveguide varied. Experimentally the linear dependence of the electric field value excited by bunches, near an output end of a semi-limited dielectric waveguide versus the interaction length is found. The 3D modeling executed by us researched possibility of the growing dependence of amplitude of a longitudinal electric field found in experiment at an output end of a waveguide from interaction length. The chronology of longi-tudinal electric field near output end on axis of system was probed and it spectral characteristic were analyzed too. The carried out researches allowed to better understanding the physical processes happening in the wakefield dielectric accelerator.В ХФТИ выполнена экспериментальная проверка принципов создания многосгусткового и многомодового кильватерного диэлектрического ускорителя. Кильватерные поля возбуждались при инжекции последовательности электронных сгустков в прямоугольном вакуумном волноводе типа R32 (72,14×34,04 мм) или типа R26 (86,36×43,18 мм), заполненном диэлектриком с относительной диэлектрической проницаемостью ε = 3.8, покрывающем две противоположные широкие стенки волновода. Частота повторения сгустков составляла 2,805 ГГц, энергия электронов была 4,5 MэВ, заряд одного сгустка составлял 0,26 нКл. Электронные сгустки, поступающие через открытый входной торец диэлектрического волновода, отклонялись поперечным магнитным полем постоянных магнитов к металлической стене волновода, свободной от диэлектрика. В зависимости от расположения магнитов вдоль оси структуры изменялась длина взаимодействия электронных сгустков с прямоугольным диэлектрическим волноводом. Выполненное нами 3D-моделирование показало линейный рост амплитуды продольного электрического поля на выходном торце волновода с длиной взаимодействия, что находится в хорошем соответствии с экспериментально полученной зависимостью. Исследовались хронологические зависимости продольного электрического поля вблизи выходного торца волновода на оси системы, получены и проанализированы спектральные характеристики колебаний поля. Проведенные исследования приводят к лучшему пониманию физических процессов, происходящих в кильватерном диэлектрическом ускорителе.У ХФТІ виконана експериментальна перевірка принципів створення багатозгусткового й багатомодового кільватерного діелектричного прискорювача. Кільватерні поля збуджувалися при інжекції послідовності електронних згустків у прямокутному вакуумному хвилеводі типу R32 (72,14×34,04мм) або типу R26 (86,36×43,18 мм), заповненому діелектриком з відносною діелектричною проникністю ε = 3.8, що покриває дві протилежні широкі стінки хвилеводу. Частота повторення згустків становила 2,805 ГГц, енергія електронів була 4,5 MеВ, заряд одного згустка становив 0,26 нКл. Електронні згустки, що надходили через відкритий вхідний торець діелектричного хвилеводу, відхилялися поперечним магнітним полем постійних магнітів до металевої стіни хвилеводу, вільної від діелектрика. Залежно від розташування магнітів уздовж осі структури змінювалася довжина взаємодії електронних згустків із прямокутним діелектричним хвилеводом. Виконане нами 3D-моделювання показало лінійне зростання амплітуди поздовжнього електричного поля на вихідному торці хвилеводу з довжиною взаємодії, що перебуває в гарній відповідності до експериментально отриманої залежності. Досліджувалися хронологічні залежності поздовжнього електричного поля поблизу вихідного торця хвилеводу на осі системи, отримані й проаналізовані спектральні характеристики коливань поля. Проведені дослідження призводять до кращого розуміння фізичних процесів, що відбуваються в кільватерному діелектричному прискорювачі

Frequency dependence of magnetothermal properties for magnetic fluid and magnetically functionalized implants

Heating of the magnetic nanoparticles in AC magnetic field is the effect promising for application in medicine. The mechanisms of heating in AC-magnetic field implies nontrivial dependence of the power dissipated by magnetic nanoparticles on frequency. With the use of a reconfigurable experimental setup, this frequency-dependent magnetic heating was measured on two characteristic examples: the magnetite nanoparticles conventionally used in medicine and polymer coating with micrometer sized magnetite particles. The saturation of the heating power with frequency is shown that is more pronounced for the second case of microparticles

Topological Defects as Seeds for Eternal Inflation

We investigate the global structure of inflationary universe both by analytical methods and by computer simulations of stochastic processes in the early Universe. We show that the global structure of the universe depends crucially on the mechanism of inflation. In the simplest models of chaotic inflation the Universe looks like a sea of thermalized phase surrounding permanently self-reproducing inflationary domains. In the theories where inflation occurs near a local extremum of the effective potential corresponding to a metastable state, the Universe looks like de Sitter space surrounding islands of thermalized phase. A similar picture appears even if the state $\phi = 0$ is unstable but the effective potential has a discrete symmetry $\phi \to =-\phi$. In this case the Universe becomes divided into domains containing different phases. These domains will be separated from each other by domain walls. However, unlike ordinary domain walls, these domain walls will inflate, and their thickness will exponentially grow. In the theories with continuous symmetries inflation generates exponentially expanding strings and monopoles surrounded by thermalized phase. Inflating topological defects will be stable, and they will unceasingly produce new inflating topological defects. This means that topological defects may play a role of indestructible seeds for eternal inflation.Comment: 21 pages, 17 figures (not included), Stanford University preprint SU--ITP--94--

Клиническое исследование отечественного фибринселективного тромболитического препарата Фортелизин® (III фаза)

The clinical trial of fibrinselective thrombolytic agent Fortelyzin® (III phase) showed the comparative efficacy and safety with Actilyse® in patients with acute myocardial infarction and obtained data permitted to recommend it for clinical usage.Проведенное исследование лекарственного препарата Фортелизин®, вводимого болюсно и болюсно-инфузионно у больных с острым инфарктом миокарда с подъемом сегмента ST, показало сравнимую с Актилизе® эффективность и безопасность исследуемого препарата и позволило рекомендовать его для медицинского применения

From the Big Bang Theory to the Theory of a Stationary Universe

We consider chaotic inflation in the theories with the effective potentials phi^n and e^{\alpha\phi}. In such theories inflationary domains containing sufficiently large and homogeneous scalar field \phi permanently produce new inflationary domains of a similar type. We show that under certain conditions this process of the self-reproduction of the Universe can be described by a stationary distribution of probability, which means that the fraction of the physical volume of the Universe in a state with given properties (with given values of fields, with a given density of matter, etc.) does not depend on time, both at the stage of inflation and after it. This represents a strong deviation of inflationary cosmology from the standard Big Bang paradigm. We compare our approach with other approaches to quantum cosmology, and illustrate some of the general conclusions mentioned above with the results of a computer simulation of stochastic processes in the inflationary Universe.Comment: No changes to the file, but original figures are included. They substantially help to understand this paper, as well as eternal inflation in general, and what is now called the "multiverse" and the "string theory landscape." High quality figures can be found at http://www.stanford.edu/~alinde/LLMbigfigs

NESTOR: A neutrino particle astrophysics underwater laboratory for the Mediterranean

Abstract An underwater neutrino astrophysics laboratory, to be located in the international waters off the Southwest of Greece, near the town of Pylos is now under construction. In the last two years a group of physicists from Greece and Russia have carried out two demonstration experiments in 4km deep water, counting muons and verifying the adequacy of the deep sea site. Plans are presented for a 100, 000 m 2 high energy neutrino detector composed of a hexagon of hexagonal towers, with 1176 optical detector units. A progress report is given and the physics potential of a siggle tower with 168 phototubes (currently under construction) is described

Beam-target helicity asymmetry e in K0 Λ and K0 Σ0 photoproduction on the neutron

We report the first measurements of the E beam-target helicity asymmetry for the γ - n - →K0Λ and K0Σ0 channels in the energy range 1.70≤W≤2.34 GeV. The CLAS system at Jefferson Lab uses a circularly polarized photon beam and a target consisting of longitudinally polarized solid molecular hydrogen deuteride with low background contamination for the measurements. The multivariate analysis method boosted decision trees is used to isolate the reactions of interest. Comparisons with predictions from the KaonMAID, SAID, and Bonn-Gatchina models are presented. These results will help separate the isospin I=0 and I=1 photocoupling transition amplitudes in pseudoscalar meson photoproduction