Peculiarities of dynamics of Dirac fermions associated with zero-mass lines

Zero-mass lines result in appearance of linear dispersion modes for Dirac fermions. These modes play an important role in various physical systems. However, a Dirac fermion may not precisely follow a single zero-mass line, due to either tunneling between different lines or centrifugal forces. Being shifted from a zero-mass line the Dirac fermion acquires mass which can substantially influence its expected "massless" behavior. In the paper we calculate the energy gap caused by the tunneling between two zero-mass lines and show that its opening leads to the delocalization of linear dispersion modes. The adiabatic bending of a zero-mass line gives rise to geometric phases. These are the Berry phase, locally associated with a curvature, and a new phase resulting from the mass square asymmetry in the vicinity of a zero-mass line.Comment: 6 pages, 4 figures. In the second version some references were added and minor changes were made in the introductio

Slowly Rotating Non-Abelian Black Holes

It is shown that the well-known non-Abelian static SU(2) black hole solutions have rotating generalizations, provided that the hypothesis of linearization stability is accepted. Surprisingly, this rotating branch has an asymptotically Abelian gauge field with an electric charge that cannot vanish, although the non-rotating limit is uncharged. We argue that this may be related to our second finding, namely that there are no globally regular slowly rotating excitations of the particle-like Bartnik-McKinnon solutions.Comment: 8 pages, LaTe

Model for integrating monetary and fiscal policies to stimulate economic growth and sustainable debt dynamics

This article examines the main integration trends of the state's monetary and fiscal policy in influencing economic growth and maintaining the sustainability of public debt. It is argued that the relationship between these trends of macroeconomic regulation is predetermined, on the one hand, by the potentially negative impact of fiscal expansion from the point of view of inflation, and by the negative impact of a likely state default in failing to refinance the debt from the Ministry of Finance, on the other hand. The paper studies the selected array of statistical data using the fiscal policy multipliers concept, the relationship between the effect of increase/decrease in budget expenditures, the slowdown in economic activity and the efforts by the Central Bank to offset fiscal measures, on the one hand, and the ratio of an increase/decrease in budget revenues and debt expenditures used to finance the budget investments, on the other hand. It is revealed that the investments are effective if implementing budget expenditures in the presence of the GDP gap and unrealized expectations of economic agents, while reducing spending in such a situation will intensify the recession. The GDP growth determined by these investments should provide the tax effect sufficient to cover the expenses. Otherwise, there can be negative effects of debt that establishes the need for measures to refinance public debt by the Central Bank. The conclusions of the paper can be used to assess the possible integration of monetary and fiscal policy based on various states.peer-reviewe

The country's economic growth models and the potential for budgetary, monetary and private financing of gross domestic product growth

This article examines the financing of GDP growth within the framework of catch-up, evolutionary and dynamic models of economic development. Methods/statistical analysis: using the principles of the Solow model and the Cobb-Douglas function, an analysis of the nature of the models has been carried out, considering the processes of capital accumulation, the rate of growth of the workforce, and various aggregate factor productivities. With the help of historical logic and statistical evaluation, examples of countries relating to each of the models examined are reviewed. Based on the analysis, the main ways of financing economic growth are noted: both the state ones, due to budgetary and monetary policy measures, and private ones. It has been proven that with the transition from catch-up to an evolutionary or dynamic model, the role of the state as a centralizing force is diminishing. At the same time, the specificity of a dynamic model is due to the country's objective ability to be among the technological leaders, which is predetermined by the high values of current GDP, per capita GDP, and population size. Countries with an evolutionary model of development are constrained in their ability to maintain a comparable pace of development only within separate "growth points". The main result of the work is the assessment of Russia's potential from the viewpoint of one of the models considered, based on a comparative analysis of several capital indicators, as well as a logical analysis of data on the level of GDP and population with other countries. This makes it possible to make recommendations for financing the country's GDP growth in the medium to long term. Scope/Improvements: The findings can be used in the development of Russia's financial and economic strategy up to 2030.peer-reviewe

Computation of the winding number diffusion rate due to the cosmological sphaleron

A detailed quantitative analysis of the transition process mediated by a sphaleron type non-Abelian gauge field configuration in a static Einstein universe is carried out. By examining spectra of the fluctuation operators and applying the zeta function regularization scheme, a closed analytical expression for the transition rate at the one-loop level is derived. This is a unique example of an exact solution for a sphaleron model in $3+1$ spacetime dimensions.Comment: Some style corrections suggested by the referee are introduced (mainly in Sec.II), one reference added. To appear in Phys.Rev.D 29 pages, LaTeX, 3 Postscript figures, uses epsf.st

Existence of spinning solitons in gauge field theory

We study the existence of classical soliton solutions with intrinsic angular momentum in Yang-Mills-Higgs theory with a compact gauge group $\mathcal{G}$ in (3+1)-dimensional Minkowski space. We show that for \textit{symmetric} gauge fields the Noether charges corresponding to \textit{rigid} spatial symmetries, as the angular momentum, can be expressed in terms of \textit{surface} integrals. Using this result, we demonstrate in the case of $\mathcal{G}=SU(2)$ the nonexistence of stationary and axially symmetric spinning excitations for all known topological solitons in the one-soliton sector, that is, for 't Hooft--Polyakov monopoles, Julia-Zee dyons, sphalerons, and also vortices.Comment: 21 pages, to appear in Phys.Rev.

Nanometer Structured Epitaxial Films and Foliated Layers Based on Bismuth and Antimony Chalcogenides with Topological Surface States

The thermoelectric and galvanomagnetic properties of nanometer structured epitaxial films and foliated layers based on bismuth and antimony chalcogenides were investigated, and an increase in the figure of merit Z up to 3.85 × 10-3 K-1 was observed in the Bi0.5Sb1.5Te3 films over the temperature range of 180–200 K. It is shown that an increase in the Seebeck coefficient and the change in the slope on temperature, associated with changes in the effective scattering parameter of charge carriers and strong anisotropy of scattering in the films, lead to enhance power factor due to the growth of the effective mass of the density of states. These features are consistent with the results of research of oscillation effects in strong magnetic fields at low temperatures and research of Raman scattering at normal and high pressures in the foliated layers of solid solutions (Bi, Sb)2(Te, Se)3, in which the topological Dirac surface states were observed. The unique properties of topological surface states in the investigated films and layers make topological insulators promising material for innovation nanostructured thermoelectrics

Ignition of premixed air/fuel mixtures by microwave steamer discharge

A variety of methods exists for fast and efficient combustion of air-fuel mixtures. In this study, a microwave subcritical streamer discharge is used to ignite propane-air mixtures at atmospheric pressure. The streamer is initiated at the inner surface of a dielectric tube with the help of a passive half-wave vibrator. By creating a network of ignition lines, the streamer discharge forms the network of burning channels with large total surface area. This leads to the apparent speed of combustion propagation along the cylinder in excess of 100 m/s, which is more than 200 times the laminar flame propagation speed. The axial propagation of the combustion front in a cylindrical tube filled with the air/propane mixture is investigated by high speed video recording in visible light. A simple model is presented to explain observed results

Application of deep convolutional and long short-term memory neural networks to red blood cells motion detection and velocity approximation

The paper deals with processing data obtained using nailfold high-speed videocapillaroscopy. To detect the red blood cells velocity two approaches are used. The deterministic approach is based on pixel intensities analysis for object detection and calculation of the displacement and velocity of red blood cells in a capillary. The obtained data formulate targets for the second approach. The stochastic approach is based on a sequence of artificial neural networks. The semantic segmentation network UNet is used for capillary detection. Then, the classification network GoogLeNet or ResNet is used as a feature extractor to convert masked video frames to a sequence of feature vectors. And finally, the long short-term memory network is used to approximate the red blood cells velocity. The results demonstrated that the accuracy of the mean velocity approximation in the time range of several seconds is up to 0.96. But the accuracy at each specific time moment is less accurate. So, the proposed algorithm allows the determination of the RBCs mean velocity but it doesn't allow determination of the RBCs pulsations accurate enough