Applying the ideas from microscopic objects to macroscopic stellar and galactic systems, the evolution of compact di-stars and di-galaxies is studied in the mass asymmetry coordinate. The formation of stable binary systems is analyzed. The role of symmetrization of an initially asymmetric binary system is revealed in the transformation of gravitational energy into internal energy of stars or...
The common and specific features of particle polarization in hadronic and heavy-ion collisions are discussed. The analogs of characteristics of hadronic and quark gluon media in hadronic structures are suggested.
The special attention is paid to shear viscosity and physical reasons of its smallness.
We discuss the underlying mathematical structure that suitably describes the symmetries of the Leigh-Strassler [LS] theories as marginal deformations of the 4D $\mathcal{N}$ = 4 super Yang-Mills [SYM]. We present Hopf algebras as a mathematical language suited to describe how to obtain LS theories from the SYM. The hope is obtain a bridge through which to port all the...
I present a brief review on multipole giant resonances (GR) n atomic nuclei. The origin, basic properties and present status of GR exploration are outlined. As an example, the wavelet analysis of GR fine structure, performed by collaboration of the experimentalists from iThemba Lab and theorists from BLTP JINR [1-5] is briefly described.
[1] L.M. Donaldson, C.A. Bertulani, J. Carter, V.O....
Clusters of gas atoms form a broad class of molecules bound by van der Waals-type interactions. Some weakly bound clusters exhibit universal characteristics and scale invariance linked to the famous Efimov effect, which was first experimentally confirmed in an ultracold gas of Cs atoms. The helium trimer system has long been regarded as an ideal candidate for observing Efimov states. After...
In the mathematical department of Institute of Theoretical and Experimental Physics (Moscow) in 1960s it was decided to choose a some intellectual game to compare skills of programmers working in different countries or in other words, it was necessary to select criteria to compare AI teams. In 1960s Alexander Kronrod coined slogan “Chess is drosophila of Artificial Intelligence” and ITEP...
We are reviewing known bounds on the variation of a spectral subspace (and, in particular, of an eigenvector) of a self-adjoint operator under an additive Hermitian perturbation. To this end we first recall the concept of operator angle between two subspaces of a Hilbert space. Then we recollect the spectral dispositions for which sharp norm bounds on the variation of the spectral subspace...
In the analysis of nuclear scattering data to determine resonance parameters (among other scattering variables), both the well-known $R$-matrix and Jost function methods of analysis can be used. Each method has benefits and disadvantages. A new method for fitting non-relativistic binary-scattering data and for extracting the parameters of possible quantum resonances in the compound system that...
A new variation method for solving the bound-state problem for a system of few
particles is proposed. Unlike the traditional variational approach,
where the expectation value of the Hamiltonian is minimized, i.e. just a single
quantity, in the proposed method the approximate solution is constructed by
fitting a continuum of quantities, namely, the entire function that describes
the...
We present a brief overview of some recent observational results that
challenge the validity of the standard LambdaCDM cosmology. These
results still need further verification, but their confirmation could
lead to revolutionary changes in our understanding of the construction
of our Universe.
In this talk I will review phase diagram of nuclear matter. Different temperature--density regimes will be discussed: low temperature--law density, low temperature--high density, high temperature—low density, and high temperature-- high density. Focus will be made on role of collective medium effects and possibilities of various phase transitions. Information from experiments and...
Physical questions can be obscured by basis redundancies. We discuss reparametrization invariants in the scalar sector of the general Two-Higgs-Doublet Model (2HDM). These invariants form a polynomial ring, with variables corresponding to a finite generating set. We derive six-loop renormalization group equations (RGEs) for all invariants in this set. Notably, our approach does not involve...
Computational Fluid Dynamics (CFD) serves as a powerful virtual laboratory for simulating and analysing complex fluid flow phenomena. By discretising the equations of fluid motion, CFD enables researchers, physicists, and engineers to model fluid behaviour in various areas such as astrophysics, nuclear physics, plasma physics, atmospheric physics and more. The talk will give an overview of...
A question of the optimal configuration of a finite number of particles in a plane has been a difficult problem of both physics and mathematics for many centuries. Back in 1611, Kepler posed already the question of why a snowflake has perfect hexagonal symmetry [1]. At present, increased interest in the problem of the optimal configuration in a plane is also due to the development of...
The spatial inhomogeneity kr in the electromagnetic wave and the magnetic component in it lead to non-separability of the variables of the electron and the center-of-mass in the hydrogen atom interacting with the laser pulse, and, as a consequence, to the acceleration of the atom [1,2]. We have shown that the influence of the laser polarization on the excitation, ionization and...
Quantum Simulation, the emulation of quantum system dynamics with quantum computers, is an
application of quantum computing which showcases a clear advantage over classical computing. This
advantage arises from the inherent difficulty in simulating quantum dynamics on classical systems, a
challenge that originally inspired Feynman and others to propose quantum computing.
The efficient...
Calculations of the probability densities and energies of the ground states for α-cluster nuclei ${}^{12}$C (3α), ${}^{16}$O (4α), ${}^{20}$Ne (5α), ${}^{24}$Mg (6α), ${}^{28}$Si (7α) and for nuclear
molecules ${}^{9}$Be (2α + n), ${}^{10}$Be (2α + 2 n), ${}^{10}$B (2α + n + p), ${}^{10}$C(2α + 2 p), ${}^{11}$B(2α + 2 n + p), ${}^{11}$C(2α + n + 2 p) were performed by the...
An overview of the results obtained in the framework of JINR-UNISA collaboration in
the field of theoretical research on superconducting electronics, spintronics and chaos is
presented [1-7]. The important role played by nonlinear and chaotic phenomena in
different types of Josephson structures will be discussed within the context of our present
studies and future...
The research team operates within the Department of Physics at the University of Limpopo. Their computational studies focus on a range of materials, including gold, silver, and copper nanoparticles, as well as the field of physics education. These nanoparticles are explored as potential candidates for chemical sensing and energy storage through theoretical and computational approaches....
We give a review of the modern precision table-top experiments and precision physics. Status of theory: two-body and three-body calculations. We discuss impact of precision physics on the fundamental physical constants, search for space-time variations of fundamental constants, precision determination of masses, search for new exotic forces, CP violation and electron EDM.
We consider...
Accurate estimates of (anti)neutrino spectra and luminosities are essential for assessing the possibility of detecting neutrinos from pre-supernova stars. Using the thermal quasiparticle random-phase approximation (TQRPA) method, we studied the effects of nuclear temperature on pre-supernova (anti)neutrino emission. Comparing the $\nu_e$ and $\bar\nu_e$ spectra produced in neutral- and...
Artificial Intelligence is revolutionising the way we solve complex problems in science. One example is the Physics-Informed Neural Network (PINN)—a machine learning approach that offers an effective framework for solving differential equations by embedding physical laws directly into the neural network’s training process. Unlike traditional numerical methods for solving differential...
Various nucleon-nucleon interactions are used to study the ground state structure of weakly bound three-body systems. It is found that when a hard-core nucleon-nucleon is used, a strongly attractive three-body force is required to keep the system bound in the case of a light system. However, the strength of the three-body force is substantially reduced as the atomic mass of the system...
Compact astronomical objects, historically called neutron stars, are remnants of dying stars that survived supernova explosions. They can be viewed as giant nuclei held together by gravitational forces acting against the pressure of degenerated nuclear matter.
We discuss astronomical constraints on the neutron star properties: mass, radius, temperature, age. Then we review the nuclear...
An analysis of the energy, mass and angular distributions of the binary reaction products in the heavy ion collisions allows us to construct the mechanisms of their formation in dependence on the beam energy, orbital angular momentum and structure of the colliding nuclei.
The theoretical methods [1] based on the dinuclear system (DNS) concept [2] suggested by Prof. Vadim Volkov are used to...
Neural networks serve as universal continuous function approximators in finite-dimensional spaces and can offer an alternative to finite element methods for solving partial differential equations (PDEs). Extending neural networks to neural operators, which can approximate continuous (and potentially non-linear) mappings between function spaces, is non-trivial. Neural operators are designed to...
Magnetic frustration, a situation where all interactions in the magnetic Hamiltonian can be realized either from geometry of the lattice , or from
anisotropic interactions. In some cases frustration can be strong enough to destroy magnetic long-range order in favor of a quantum disordered "spin liquid" regime. Such a state is highly sough after due to its entanglement and topological...
The theory of the Jost function provides an elegant and unified framework for determining resonance and bound states. These states are determined by 1)Solving a system of differential equations, which are equivalent to the Schrödinger equation, to obtain the Jost functions.
2)Searching for the zeros of the Jost function in the complex energy plane.
This approach has been successfully...
The traditional two-variable few-body integrodifferential equations approach is modified by introducing boundary conditions in both the hyperradial and hyperangular variables. In addition, the inclusion of the effects of higher partial waves of the interaction potential is also modified. The new approach reproduces results obtained by an exact method for boson systems. These results confirm...
A specific feature of the deep-inelastic collisions is the high loss of kinetic energy of the collision heavy ions. This means that the latter become highly excited during the collision. The mechanism of the energy loss of the colliding nuclei is described within the theory of Brownian motion as classical friction due to the coupling of the relative motion of heavy ions to the internal...
One of the common approaches toward solving the Faddeev and Faddeev-Yakubovsky equations is the use of partial-wave expansion of the solution sought, resulting in the reduction of the Faddeev equations to a set of two-dimensional coupled equations, which are amenable to numerical solution. For systems interacting via a force strong repulsive core lots of partial waves are necessary to achieve...
In last two decades identification of topological properties in low dimensional quantum materials (specifically one and two-dimensional) has been one of the principal area of investigation condensed matter research. It resulted in several impressive discoveries, e.g., topological insulators, topological superconductors, topological Hall effect etc. The related underlying theory had been built...
The light nuclei 18O, 12C, 9Be and 6Li used as target and projectile nuclei in the many experimental studies of the nuclear reactions, including Flerov Laboratory of Nuclear Reaction (JINR). The study of the structure of these nuclei is necessary for theoretical description of such reactions. Wave functions of the ground state of the 18O, 12C, 9Be and 6Li nuclei in the alpha-cluster model are...
We investigate soliton collisions in scalar field theories in 1+1
dimensions and a model, which interpolates between the sine-Gordon
theory, phi4 theory and a model with sextic potential. Various resonant
structures emerging in this model because of energy transfer between the
modes of excitation. We also emphasise the role of radiation and
oscillon formation in the collision process.
The numerical solution of the time-dependent Schrodinger equation (TDSE) [1] for outer neutrons and protons of colliding nuclei are used for description of nucleon-transfer reactions. The calculated cross sections show satisfactory agreement with the experimental data for representative set of reactions. The cross sections for the production of the isotopes ${}^{196,198}$Au in...
The presentation discusses the experimentally observed formation and growth of a chromium silicide layer in a silicon wafer with a deposited chromium layer. The chromium silicide layer forms and grows at the boundary between silicon and chromium. The time dependence of the layer thickness is first described by linear functions with different growth rates: rapid growth is replaced by slow...
We investigate the framework of extended dual Quantum Chromodynamics (QCD), wherein confinement and mass generation are described through a dual superconducting model of the QCD vacuum. By extending the conventional dual QCD approach—typically centered on the Abelian projection and monopole condensation—we incorporate additional dual gauge degrees of freedom and scalar fields associated with...
Quantum Computing promises to solve specific classes of problems exponentially faster than any possible classical counterpart. However, testing this result in real life requires a large-scale universal error-correcting fault-tolerant quantum computer, which has not yet been built. We live in the age of noisy intermediate-scale quantum computers (NISQ) with several hundreds of noisy qubits. One...
This study investigates the structural, electronic and mechanical properties of the half-Heusler compounds: VSnPt, NbSnPt and NbSnPt employing density functional theory (DFT) within the generalized gradient approximation (GGA). The equilibrium lattice constants, bulk moduli and their pressure derivatives were computed and compared with the related theoretical data. The results indicate that...
The study of exotic nuclei, particularly those that are weakly bound, continues to attract significant interest due to their unique structural and reaction properties. In this work, we investigate the influence of resonant states on the breakup process and its interplay with other reaction channels such as elastic scattering and fusion cross sections. Specifically, we examine the 6Li and 7Li...
Abstract:
Relatively to the atomic constituents’ counterparts, the neutron is singular as it is sensitive to the four fundamental interactions: strong, weak, electromagnetic, and gravitational. This multi-sensitivity makes neutron wave-matter optics a particularly versatile tool for testing quantum mechanics specifically and fundamental physics concepts in general.
The lifetime of a free...
Magnetic frustration, a situation where all interactions in the magnetic Hamiltonian can be realized either from geometry of the lattice , or from
anisotropic interactions. In some cases frustration can be strong enough to destroy magnetic long-range order in favor of a quantum disordered "spin liquid" regime. Such a state is highly sough after due to its entanglement and topological...
