arXiv subjects

S. A. Trigger

Publications and source records attributed to S. A. Trigger.

At least 19 recordsLinked to original sources

arXiv2020

Electromagnetic field energy in an absorptive medium with temporal and spatial dispersion

General relations for electromagnetic field energy outside the transparency domain are proposed. It is shown that charged particle contribution to the energy of electromagnetic perturbations in the general case can be described in terms of a bilinear combination of the dielectric polarizability of the medium. The explicit form of such contribution is found. The relations obtained are used to generalize the Planck law to the case of an absorptive medium.

cond-mat.stat-mech↗

arXiv2020

Primordial plasma: influence of non-ideality on equilibrium radiation

The asymptotic behavior of the equilibrium radiation in Maxwellian plasma is studied for the low--frequency region. It is shown, that the equilibrium radiation can essentially deviate from the Planck law even for a weakly non-ideal plasma. The deviation from the Planck distribution is described by the transverse dielectric permittivity which takes into account both frequency and spatial dispersion. The influence of plasma non-ideality increases with the non-ideality parameter in the dielectric permittivity. The spectral energy distribution of the equilibrium radiation essentially changes in the region of observable frequencies. At asymptotically low frequencies, the equilibrium radiation begins to exhibit power behavior instead the logarithmic one. The results indicate that the spectral energy distribution of radiation could be different then the Planck one in the primordial plasma of the early Universe.

physics.plasm-ph↗

arXiv2020

Primordial plasma: influence of non-ideality on equilibrium radiation

The asymptotic behavior of the equilibrium radiation in Maxwellian plasma is investigated for the region of low frequencies. It is shown, that already for a weakly non-ideal plasma the equilibrium radiation can essentially deviate from the Planck law. The deviation from the Planck distribution is described by the transverse dielectric permittivity which takes into account both frequency and spatial dispersion. The influence of plasma non-ideality increases with increase of the non-ideality parameter in the in the dielectric permittivity. The spectral energy distribution of the equilibrium radiation essentially changes in the region of observable frequencies. At asymptotically low frequencies there is transfer from logarithmic to power behavior of the equilibrium radiation. The results indicate that in the primordial plasma of Early Universe the spectral energy distribution of radiation could be different then the Planck one.

physics.plasm-ph↗

arXiv2019

From Coulomb to the effective interaction: application to Bose condensation

The expression for the short-range effective interaction potential of "quasinulei"\, is derived based on the model of the "pure"\, Coulomb interaction. This model represents the equilibrium Coulomb system (CS) of interacting electrons and the identical nuclei, using the adiabatic approximation for nuclei and an arbitrary strong (in general) interaction for the electronic subsystem. On the basis of general properties of Coulomb interaction it is shown that the Fourier-component of the pair effective potential between "quasinuclei" possesses discontinuity at the wave vector $q=0$. This discontinuity is essential for the Bose condensed systems as HeII and the rarified Alkali metals at temperatures lower than the Bose condensation transition, since there are macroscopic quantity of quasiparticles with the momentum $q=0$. In particular, it is shown that for the single-particle excitations can exist the gap which disappears in the normal state. The value of this gap is estimated. The problem of generalization of the obtained results for the case of a strong electron-nuclei (or electron-point ion system) is discussed.

physics.gen-ph↗

arXiv2018

To the Problem of Electromagnetic Field Energy in the Medium with Temporal and Spatial Dispersion Outside the Transparency Domain

The problem of calculation of electromagnetic field energy outside the transparency domain is discussed. It is shown that charged particle contribution to the energy of electromagnetic perturbations in the general case can be described in terms of bilinear combination of the dielectric polarizability of the medium. The explicit form of such contribution is found. The relations obtained are used to generalize the Planck's law to the case of absorptive medium.

physics.plasm-ph↗

arXiv2017

Longitudinal electric field: from Maxwell equation to non-locality in time and space

In this paper we use the classical electrodynamics to show that the Lorenz gauge can be incompatible with some particular solutions of the d Alembert equations for electromagnetic potentials. In its turn, the d Alembert equations for the elec- tromagnetic potentials is the result of application of the Lorenz gauge to general equations for the potentials. The last ones is the straightforward consequence of Maxwell equations. Since the d Alembert equations and the electromagnetic poten- tials are necessary for quantum electrodynamics formulation, one should oblige to satisfy these equations also in classical case. The solution of d Alembert equations, which modifies longitudinal electric field is found. The requirement of this modifi- cation follows from the necessity to satisfy the physical condition of impossibility of instantaneous transferring of interaction in space.

physics.gen-ph↗

arXiv2016

On the ground state energy of the inhomogeneous Bose gas

Within the self-consistent Hartree-Fock approximation, an explicit expression for the ground state energy of inhomogeneous Bose gas is derived as a functional of the inhomogeneous density of the Bose-Einstein condensate. The results obtained are based on existence of the off-diagonal long-range order in the single-particle density matrix for systems with a Bose-Einstein condensate. This makes it possible to avoid the use of anomalous averages. The explicit form of the kinetic energy, which differs from one in the Gross-Pitaevski approach, is found. This form is valid beyond the Hartree-Fock approximation and can be applied for arbitrary strong interparticle interaction.

cond-mat.quant-gas↗

arXiv2015

Frequency depending permittivity of the Coulomb system with Bose-Einstein condensate

The second-order singularity is found in the low-frequency region of the permittivity of a homogeneous and isotropic system of charged particles consisting of electrons and boson nuclei. This singularity is caused by the existence of a Bose-Einstein condensate for nuclei. The result obtained leads to the existence of the "nuclei superconductivity", which can be experimentally verified in superfluid He II. The results of the proposed an experiment can be considered as a direct proof of the existence of a Bose-Einstein condensate in superfluid He II.

physics.gen-ph↗

arXiv2014

Analysis of linear and nonlinear conductivity of plasma-like systems on the basis of the Fokker-Planck equation

The problems of high linear conductivity in an electric field, as well as nonlinear conductivity, are considered for plasma-like systems. First, we recall several observations of nonlinear fast charge transport in dusty plasma, molecular chains, lattices, conducting polymers and semiconductor layers. Exploring the role of noise we introduce the generalized Fokker-Planck equation. Second, one-dimensional models are considered on the basis of the Fokker-Planck equation with active and passive velocity-dependent friction including an external electrical field. On this basis it is possible to find the linear and nonlinear conductivities for electrons and other charged particles in a homogeneous external field. It is shown that the velocity dependence of the friction coefficient can lead to an essential increase of the electron average velocity and the corresponding conductivity in comparison with the usual model of constant friction, which is described by the Drude-type conductivity. Applications including novel forms of controlled charge transfer and non-Ohmic conductance are discussed.

physics.plasm-ph↗

arXiv2014

Universality of phonon-roton spectrum in liquids and superfluidity of He II

Based on numerous experimental data on inelastic neutron and X-ray scattering in liquids, we assert that the phonon-roton spectrum of elementary excitations, predicted by Landau for superfluid helium, is a universal property of the liquid state. We show that the existence of the roton minimum in the spectrum of collective excitations is caused by the short-range order in liquids. Using the superfluidity criterion, we assume that one more branch of collective excitations should exist in He II, whose energy spectrum differs from the phonon-roton spectrum.

cond-mat.other↗

arXiv2014

Jeans instability and anti-screening in gravitational-antigravitational model of Universe

The hypothesis of antigravitational interaction of elementary particles and antiparticles is considered on the basis of the simple two-component hydrodynamic model with gravitational repulsion and attraction. It is shown increasing of the Jeans instability rate, the presence of antiscreening and the dominative role of the gravitational repulsion as a possible mechanism for spatial separation of matter and antimatter in Universe, as well as the observable acceleration of the far galaxies. The sound wave is found for the two-component gravitational-antigravitational system, which starts for k = 0 in the case of annihilation neglecting. The suggested approach permits to reestablish the idea about baryon symmetry of Universe, causing its steady flatness of the large scale and accelerated Universe expansion.

physics.gen-ph↗

arXiv2013

Virial theorem and Gibbs thermodynamic potential for Coulomb systems

Using the grand canonical ensemble and the virial theorem, we show that the Gibbs thermodynamic potential of the non-relativistic system of charged particles is uniquely defined by single-particle Green functions of electrons and nuclei. This result is valid beyond the perturbation theory with respect to the interparticle interaction.

cond-mat.stat-mech↗

arXiv2013

Aharonov--Bohm effect, electrodynamics postulates, and Lorentz condition

The problem of the relation between the Ahronov-Bohm effect and traditional postulates of electrodynamics, which claim that only electric and magnetic fields are observable, is resolved by denial of the statement about validity of the Maxwell equations for microscopic fields. We proceed from the idea that the Maxwell equations, as the generalization of experimental data, are valid only for averaged values. We show that microscopic electrodynamics should be based on postulation of the d'Alembert equations for four-vector of the electromagnetic field potential. The Lorentz condition is valid only for the averages and provides the implementation of the Maxwell equations for averages. This concept eliminates the problem of electromagnetic field quantization and provides the correctness of all known results of quantum electrodynamics. Therefore, the "virtuality" of the longitudinal and scalar photons has a formal mathematical character, conditioned by the Maxwell equations for averaged fields. The longitudinal and scalar photons provide not only the Coulomb interaction of charged particles, but also allow the electrical Aharonov-Bohm effect.

quant-ph↗

arXiv2013

Universality of rotons in liquids, generalized superfluidity criterion and helons in helium II

An analysis of experimental data shows that, in addition to phonon--roton excitations in superfluid helium, there necessarily exist at least one branch of elementary excitations whose energy spectrum strongly depends on temperature. On this basis, the Landau superfluidity criterion is generalized for several branches of elementary excitations, taking into account that the critical velocity should vanish during the phase transition of liquid helium from the superfluid state to the normal state. We suppose that a new spectrum of excitations with a gap, depending on interparticle interaction, corresponds to the transition of helium to superfluid state. This gap exists only in superfluid state and disappears at the transition temperature to normal state. The phonon-roton branch of excitations has no crucial influence on superfluidity. Rotons, as well as phonons, are not the specific excitations for the superfluid helium, but exist as universal excitations in liquid state, and form the continuous branch of excitations in different liquids. This point of view is confirmed experimentally and numerically.

cond-mat.stat-mech↗

arXiv2013

Metal - non-metal transition and the second critical point in expanded metals

Based on the non-relativistic Coulomb model within which the matter is a system of interacting electrons and nuclei, using the quantum field theory and linear response theory methods, opportunity for the existence of the second critical point in expanded metals, which is directly related to the metal--nonmetal transition, predicted by Landau and Zeldovitch, is theoretically justified. It is shown that the matter at the second critical point is in the state of true dielectric with zero static conductivity. The results obtained are in agreement with recent experiments for expanded metals. The existence of the second critical point is caused by the initial multi-component nature of the matter consisting of electrons and nuclei and the long-range character of the Coulomb interaction. (Accepted in PTEP)

cond-mat.stat-mech↗

arXiv2012

Elementary excitations and heat capacity singularity in superfluid helium

We proceed from the premise that the spectrum of elementary excitations in the normal component in Landau's theory of superfluidity should depend on the superfluid helium temperature. This leads to generalization of the Landau superfluidity criterion. On this basis, taking into account available experimental data on inelastic neutron scattering, it is shown that, in addition to phonon--roton excitations, there is one more type of elementary excitations in superfluid helium, which we called helons. The energy spectrum with such a momentum dependence was first proposed by Landau. The helon energy spectrum shape and its temperature dependence make it possible to explain the singular behavior of the heat capacity of superfluid helium near its phase transition to the normal state.

cond-mat.stat-mech↗

arXiv2012

Theory of degenerate Bose gas without anomalous averages

Theory of a weakly non-ideal Bose gas in the canonical ensemble is developed without assumption of the C-number representation of the creation and annihilation operators with zero momentum. It is shown that the pole of the "density-density" Green's function exactly coincides with the Bogolybov's phonon-roton spectrum of excitations. At the same time, a gap exists in the one-particle excitation spectrum . This gap is related to the density of particles in the "condensate".

cond-mat.stat-mech↗

arXiv2012

Ground state energy in the external field and the problem of density functional approximations

Based on the Schrodinger equation, exact expressions for the non-relativistic particle energy in the local external field and the external field potential are derived as inhomogeneous density functionals. On this basis, it is shown that, when considering more than two noninteracting electrons, the energy of such a system cannot be an inhomogeneous density functional. The result is extended for the system of interacting electrons. This means that the Hohenberg-Kohn lemma which assert that in the ground state to each inhomogeneous density corresponds only one potential of the external field cannot be a justification of the existence of the universal density functional in the general case. At the same time, statements of the density functional theory remain valid when considering any number of noninteracting ground-state bosons due to the Bose condensation effect.

cond-mat.stat-mech↗