It is shown that the thermal counterflow in superfluid helium placed in a magnetic field leads to the appearance of an electric field in the surrounding space. The effect is due to the counterflow nature of thermal conductivity in superfluid systems: heat transfer in such systems is associated with the movement of the normal component, but the average mass flow carried by the normal component...
Topological solitons under certain conditions can freely propagate without radiation in the discrete systems of Josephson junctions [1]. These solutions are known as embedded solitons [2]. The dynamics of soliton in the array of the small Josephson junctions which contain a ferromagnet (SFS, SFIS) in their structure and where the intercell inductance is taken into account is investigating. For...
High-temperature superconductors with layered structure, such as $\rm YBa_2 Cu_3 O_{7-\delta}$,$\rm Bi_2Sr_2CaCu_2O_{8+\delta}$, $\rm La_{2-\delta}Sr_\delta CuO_4$ are anisotropic and strongly nonlinear Josephson plasma media. Such layered superconductors favor propagation of electromagnetic waves in the THz frequency range which is promising for various applications. In close analogy to...
We present the results of the investigation of X-ray photoemission spectra (XPS) for the strongly correlated electron system with both local and nonlocal correlations (correlated hopping). We consider the Falicov–Kimball model, the simplest model of strongly correlated electrons, extended by the inclusion of the interaction with deep core-hole state. Despite its simplicity, the Falicov–Kimball...
We investigate the low-temperature properties of the spin-1/2 antiferromagnetic Heisenberg model on the frustrated three-leg [1-2] and four-leg [3-5] tubes with almost dispersionless (almost flat) lowest magnon band placed in an external magnetic field. The aim of our study is to develop a systematic theory of low-temperature high-field properties of the models by hand. Using standard operator...
We consider the spin-1/2 antiferromagnetic isotropic Heisenberg model on a kagome-lattice bilayer in the presence of an external magnetic field. We include an interlayer frustration term and study the case of ideal frustration when the nearest-neighbor intralayer interactions and the frustrating interlayer interactions are of the same strength. In this case, a completely dispersionless (flat)...
An explanation is proposed for the recently observed in optical spectra of monolayer graphene giant increase in the Drude-peak width under applied uniaxial strain. We argue that the underlying mechanism of this increase can be based on resonant scattering of carriers from inevitably present impurities such as adsorbed atoms that can be described by the Fano-Anderson model. We demonstrate that...
Ion beam therapy is one of the most progressive methods in cancer treatment. Studies of water radiolysis process show that under the action of ionizing irradiation in the medium of biological cell different atomic and molecular species occur. The most long-living among them are hydrogen peroxide (H$_2$O$_2$) molecules. But the role of hydrogen peroxide molecules in the deactivation of the DNA...
Under the natural conditions, DNA macromolecule takes the form of a double helix which structure is stabilized by water molecules and metal ions. The organization of the ion-hydration environment of the macromolecule depends on a region of the double helix. In particular, in the minor groove of the macromolecule the water molecules are highly structured and the spine of water molecules,...
The research is based on the ideology that the destructive centers of cyanides in living microorganisms are respiratory centers, the destruction of cyanides is investigated. The phenomenological equations are used in the work. These equations are not linear and approximate analytical solutions are found for them. The kinetics of destruction of previously experimentally detected dependencies on...
Destabilized magnetohydrodynamic (MHD) eigenmodes can transfer the energy and momentum from the region where particles (e.g., fast ions) drive the plasma instability to another region, where the destabilized waves are damped. This phenomenon named “spatial channeling” (SC) was predicted in [1,2]. A key element of the SC is that the energy and momentum of particles driving the instability are...
The critical behavior of a mixture of two types of ultracold bosons on the optical lattice was studied. The system can be described by the Bose-Hubbard model. It is known that the system can be in a superfluid or in a Mott insulator state, depending on the hopping parameter and chemical potential. The interaction between different types of particles drastically changes the phase diagram. In...
Granular materials under the external perturbations show a diversity of structural transformations which characterized by different symmetries. Their rigorous classification in terms of phase transitions seems very attractable (nevertheless, still questionable). Intriguing question is: can we use the information extracted from studying of structural transformations characters in granular...
We consider a class of spiking neuron models defined by a set of conditions typical for basic threshold-type models, such as leaky integrate-and-fire model and some artificial neurons. A series of impulses, representing a point renewal process, is applied to a neuron. Each output impulse is fed back to the neuron after a fixed time delay, $\Delta$. This impulse acts as an impulse received...
We consider the property of compressibility of the binary granular mixture paying attention to their local structurization. The Kirkwood-Buff theory [1] has been used in order to provide theoretical description of the free volume and compessibility of model bi-component system [2]. Relevant characters of compactivity has been expressed in terms of partial properties of species. For theoretical...
One of the most remarkable manifestations of quantum properties of superconductors and superfluids is formation of Josephson vortices (JVs), alias fluxons, in long Josephson junctions.
In this work, we studied weak- and strong-coupled systems of two parallel superfluid rings with different angular momenta. Atomic Bose-Einstein condensates loaded in a dual-ring trap (two rings separated by a...
Hawking radiation is one of the most fascinating phenomena taking place near the black hole horizon. Featuring both gravitational and quantum properties this effect is extremely hard to observe on the real objects. Surprisingly, it is possible to mimic evaporation of particles on the acoustic analogs, where Bose-Einstein condensate plays a role of background giving birth for Hawking pairs....
Pyroelectric (PE) and electrocaloric (EC) properties on the ferroelectric-antiferroelectric phase boundary of ferroelectric (FE) thin films, multilayers and other low-dimensional materials can significantly differ from PE and EC properties of bulk single crystals, solid solutions and ceramics. In fact, even for FE nanoparticles, for which efficient synthesis procedures and methods for...
In contrast to conservative systems, in nonlinear media with gain and loss the dynamics of localized topological structures exhibit many unique features that can be controlled externally. We propose a robust mechanism to perform topological transformations changing characteristics of dissipative vortices and their complexes in a controllable way. We show that a properly chosen control carries...
In recent years, there has been an increase in studies focused on the size-dependent contact angle. In the case of the sessile axial symmetric droplet, the size dependence often is explained by the contribution of the line tension to the Helmholtz free energy as a consequence, the modified Young's equation. There are two major points of view on the contribution mechanism. According to the...
Mathieu equation appears in different fields of physics and usually it's known as Schrodinger equation with cosine as potential but in more general sense it's a certain specification of confluent Heun equation. Heun equation is a second order ordinary differential equation with rational coefficients, with four regular singular points. Without loss of generality we can put these points in...
The solution of the problem of fermions scattering in one Aharonov-Bohm vortex involves constructing a one-parameter family of self-adjoint extensions. The Green function can be constructed from the corresponding solutions. The following is a comparison of quantum-mechanical scattering problem with quantum field theory problem on the search for correlation functions of fermion states. Namely,...
Axions are hypothetical particles beyond the Standard Model. Their existence is postulated to resolve the strong CP problem in QCD. The existence of the axion-like particles should modify the visible spectra of the cosmic objects due to their coupling to photons in the presence of a magnetic field, for example, inside galaxy clusters. For this reason, they were proposed as one of the...
We present the result of modelling of spectral energy distribution of the infrared source IRAS 22150+6109. The object emits an excess of radiation in far infrared band. It was interpreted to be a young massive pre-main-sequence star and the protoplanetary disk on late stage. We use radiative transfer code RADMC-3D for the simulations of spectral energy distribution. The code itself implements...
The concept of atomic covalent radius forms the basis for one of the simplest parameterizations for prediction of the covalent bond length and recovering molecular graphs from the set of interatomic distances. In the present contribution we adopt the recently proposed dataset [1] of covalent bond lengths resulting from the first-principle calculations to derive the covalent radii for H, B, C,...
Enhancement of therapeutic activity of organic drug molecules bound to nanoparticle surface has recently been highlighted as a possible way to overcome resistance of bacteria towards traditional antibiotics [1]. Investigation of the physical interactions responsible for such complexation, however, becomes challenging when nanoparticle is formed by transition metal atoms due to the need of...
The possibility of GPU usage combined with the substitution of numerical computations with the trained neural network for both relativistic and non-relativistic hydrodynamic equations yields the 104 - 106 performance boost compared to the standard numerical methods. The main idea behind the work starts from the fact that neural network is the so-called perceptron on the universal type. The...
Transport processes play a significant role in the evolution of non-equilibrium plasmas. Various instabilities which exist in such plasma can generate intense fields that interact with particles and cause the anomalous transport. The intensity of the generated fields can be high enough to cause anomalous transport exceeding the collisional one. The possible explanation of a significant...
Dwarf spheroidal galaxies (dSphs) are the most compact dark-matter-dominated objects observed so far. The Pauli exclusion principle limits the number of fermionic dark matter particles that can compose a dSph halo. This results in a well-known lower bound on their particle mass. So far, such bounds were obtained from the analysis of individual dSphs. We model dark matter halo density profiles...
The origin of dark matter (DM) is one of the most intriguing questions in modern physics.
One of the most promising DM models is the so-called `warm' dark matter (WDM) with particle mass in the range of keVs.
The signature of warm dark matter could be fewer small size dark matter halos and small mass galaxies in the early Universe (compared to the standard "cold dark matter" (CDM)...
Classification of galaxy types is one of the cornerstones for extragalactic astrophysics and observational cosmology. The most precise method of galaxy classification used by astronomers so far is the manual classification. Its major drawback, however, is the extensive usage of manpower, either from highly skilled professionals, or, in some cases (such as in Galaxy Zoo project) amateur...
We study an impact of asymmetric dark matter on properties of the neutron stars and their ability to reach the two solar masses limit, which allows us to present a new upper constraint on the mass of dark matter particle. Our analysis is based on the observational fact of existence of three pulsars reaching this limit and on the theoretically predicted reduction of the neutron star maximal...
The ultralight dark matter (ULDM) model proposes as DM particles candidates bosons with typical mass $10^{-22}$ eV, such that its de Broglie wavelength is of galactic scale ($\sim$kpc). The ULDM was among the models, that were proposed to resolve CDM tensions on the small scales, such as core-cusp and missing satellite problem. However last times it faces some difficulties between observed...
Three-dimensional electrically charged black hole with nonlinear electromagnetic field in anti-de Sitter spacetime is studied. Both static [1] and slowly rotating cases are considered. Solutions of field equations are obtained and thermodynamic behavior in extended phase space thermodynamics is examined.
[1] M. B. Tataryn, M. M. Stetsko, Int. J. Mod. Phys. D 28 (2019) 1950160.
For obtaining polarization effects in the Kerr space-time we have used algebraically special approach for Maxwell equations [1].
As a consequence, in Kinnersley tetrad Maxwell field is described only by one extremal component $\varphi_2$, and the Maxwell equations have closed-form solution [2]:
$\varphi_2= C \frac{e^{i\omega (t-\tilde{r}) + i m \phi }}{\sin\theta(r- i a \cos\theta)}...
We revisit the Polyakov Loop coupled Nambu-Jona-Lasinio model that maintains the Polyakov loop dynamics in the limit of zero temperature, which is of interest for astrophysical applications. For this purpose we re-examine the form of the potential for the deconfinement order parameter at finite baryonic densities. Secondly, and the most important, we explicitly demonstrate that a modification...
This report is devoted to lattice study of QCD equation of state (EOS) at finite baryon chemical potential and nonzero magnetic field. The simulations are performed with rooted dynamical staggered $u$, $d$, $s$ quarks at physical quark masses. In order to avoid the sign problem, the study is carried out at imaginary chemical potential and the results are analytically continued to real...
There were many phase transitions during the evolution of our Universe. The electroweak phase transition and deconfinement were two of them. The electroweak phase transition happened near 100 GeV and due to Higgs mechanism the leptons, quarks and gauge bosons gained mass. The deconfinement phase transition happened near 150 MeV and quarks combined to each other, as a result baryons and mesons...
$\qquad$According to present day results of the LHC experiment data analysis, there were no dark matter candidates found. The purpose of this work is to present a possible theoretical explanation why it could be so.
$\qquad$In our consideration, we propose a simple dark matter model of the heavy fermions described by the field $\psi$. A visible matter is modeled by the pair of scalar fields –...
The chemical freeze-out parameters in central nucleus-nucleus collisions are extracted consistently from hadron yield data within the quantum van der Waals (QvdW) hadron resonance gas model. The beam energy dependences for skewness and kurtosis of net baryon, net electric, and net strangeness charges are predicted. The QvdW interactions in asymmetric matter, $Q/B \neq 0.5$, between...
The problem of fast charged particles scattering in a thin layer of crystalline and amorphous matter is considered [1]. There is suggested an approach that allows one to consider the process of scattering in such targets from a single point of view. The approach is based on the Born and Eikonal approximations of the quantum scattering theory [2]. In the case of scattering in a crystal, special...
We consider the thermodynamical properties of an interacting boson system at ?finite temperatures and zero chemical potential within the framework of the Skyrme-like mean-fi?eld model. Self-consistency relations between the mean fi?eld and thermodynamic functions are derived. For illustration of our approach the thermodynamic properties of a $\pi$-meson system are investigated. We numerically...
The nuclear liquid-gas transition at normal nuclear densities, n∼n0=0.16 fm−3, and small temperatures, T∼20 MeV, has a large influence on analytic properties of the QCD grand-canonical thermodynamic potential. A classical van der Waals equation is used to determine these unexpected features due to dense cold matter qualitatively. The existence of the nuclear matter critical point results in...
Bose-Einstein condensation (BEC) and particle number fluctuations are considered in the gas of bosons with repulsive interactions between particles. Two different mean-field models of the interacting Bose gas are studied. They provide rather different predictions for the BEC transition temperatures and the scaled variances of particle number fluctuations. The behavior of the BE condensate in...
The production of backward nucleons, $N(180^\circ)$, at $180^\circ $ in the nuclear target rest frame in proton-nucleus (p~+~$A$) collisions is studied. The backward nucleons appearing outside of the kinematically allowed range of proton-nucleon (p~+~$N$) reactions are shown to be due to secondary reactions of heavy baryonic resonances produced inside the nucleus. Baryonic resonances $R$...
The Standard Model (SM) is the best theory of particle physics for today, giving precise predictions. However, it fails to explain some fundamental problems such as the strong CP problem, neutrino oscillations, matter-antimatter asymmetry, and the nature of dark matter and dark energy.
To resolve these problems it seems reasonable to add new particles to the SM. Since these particles are not...
