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B. P. Kosyakov

Publications and source records attributed to B. P. Kosyakov.

At least 19 recordsLinked to original sources

Can Euclidean lattice quantum field theory be analytically continued into Minkowski space?

In this paper, we attempt to test whether Euclidean lattice quantum field theory can be analytically continued into Minkowski space via the inverse Wick rotation. Our discussion indicates that such an analytical continuation is impossible without first taking the lattice theory to the continuum limit. The obstacle is that discretization of spacetime converts local quantum field theory into a theory with a nonlocal form factor, for which the Wick rotation is infeasible.

hep-th

Why is ${\rm Pb}^{208}$ the heaviest stable nuclide?

In an effort to understand nuclei in terms of quarks we develop an effective theory to low-energy quantum chromodynamics in which a single quark contained in a nucleus is driven by a mean field due to other constituents of the nucleus. We analyze the reason why the number of $d$ quarks in light stable nuclei is much the same as that of $u$ quarks, while for heavier nuclei beginning with ${\rm Ca}^{40}$, the number of $d$ quarks is greater than the number of $u$ quarks. To account for the finiteness of the periodic table, we invoke a version of gauge/gravity duality between the dynamical affair in stable nuclei and that in extremal black holes. With the assumption that the end of stability for heavy nuclei is dual to the occurrence of a naked singularity, we find that the maximal number of protons in stable nuclei is $Z_{\max}^{\rm H}\approx 82$.

nucl-th

The pedagogical value of the four-dimensional picture I: Relativistic mechanics of point particles

We outline two subjects of relativistic mechanics: (i) the set of allowable world lines, and (ii) the origin of the relativistic law of dynamics governing point particles. We show that: (i) allowable world lines in the classical theory of particles and fields are quite simple geometric objects as opposed to their associated three-dimensional trajectories, and (ii) Newton's second law requires neither modification nor generalization, it should be only smoothly embedded in the four-dimensional geometry of Minkowski spacetime to yield the dynamical law for relativistic particles.

physics.class-ph

The pedagogical value of the four-dimensional picture II: Another way of looking at the electromagnetic field

The concept of electromagnetic field can be neatly formulated by recognizing that the simplest form of the four-force is indeed feasible. We show that Maxwell's equations almost entirely stem from the properties of spacetime, notably from the fact that our world has dimension d = 4. Their complete reconstruction requires three additional assumptions which are seemingly divorced from geometry, but, actually, may have much to do with the spacetime properties.

physics.class-ph

How to detect the lightest glueball

We suggest a procedure of the lightest glueball detection in a head-on collision of photons whose center-of-mass energy is in the range $1.3-2$ GeV. Recent evidence for the scattering of light by light in experiments at the Large Hadron Collider is used as a phenomenological basis of our suggestion. With this evidence, the cross section of the lightest glueball creation in the $γγ$ collisions is estimated to be $\sim 60\,$nb. The predominant mode of the lightest glueball decay, predicted from the gauge/gravity duality, proves to be the decay into two neutral vector mesons $ρ^0ρ^0$. Because $ρ^0$ decays into $π^+π^-$, a drastic increase in the $π^+π^-π^+π^-$ yield is expected as the center-of-mass energy of the colliding photons approaches the value of the lightest glueball mass. This fact may be regarded as the unique signature of the lightest glueball detection.

hep-ph

Nonlinear electrodynamics with the maximum allowable symmetries

Recently Bandos, Lechner, Sorokin, and Townsend [arXiv:2007.09092] have discovered that Maxwell's electrodynamics can be generalized so that the resulting nonlinear theory preserves both conformal invariance and SO(2) duality-rotation invariance. Their result can be derived in a simpler way.

hep-th

Correspondence between the physics of extremal black holes and that of stable heavy atomic nuclei

Extremal black holes are immune of Hawking evaporation. On the other hand, some heavy atomic nuclei feature extraordinary stability to spontaneous transmutations changing their mass numbers. The fact that extremal black holes and stable nuclei share a common trait, that of defying spontaneous ejection of their constituents, suggests that a good part of nuclear physics is modelled on physics of extremal black holes through a simple version of gauge/gravity duality. A general criterion for discriminating between stable and unstable microscopic systems can be formulated to gain a new insight into some imperfectly understood phenomena, such as instability of truly neutral spinless particles (Higgs bosons, $π_0$, quarkonia, glueballs).

hep-th

Self-interaction in classical gauge theories and gravitation

To develop a systematic treatment of the self-interaction problem in classical gauge theories and general relativity, we study tenable manifestations of self-interaction: topological phases, and rearrangements of degrees of freedom appearing in the action. We outline the occurrence of topological phases in pure field systems. We show that the rearranged Maxwell-Lorentz electrodynamics is a mathematically consistent and physically satisfactory theory which describes new entities, dressed charged particles and radiation. We extend this analysis to cover different modifications of the Maxwell-Lorentz electrodynamics and the SU(N) Yang-Mills-Wong theory. We take a brief look at a subtle mechanism of self-interaction in classical strings. Turning to general relativity, we note that the total energy and momentum of a system with nontrivial topological content, such as a black hole, are ambiguous, coordinatization-dependent quantities, which resembles the situation with paradoxical decompositions in the Banach-Tarski theorem.

hep-th

No-go theorem for the classical Maxwell-Lorentz electrodynamics in odd-dimensional worlds

If the conventional Maxwell--Lorentz formulation of classical electrodynamics is adopted in a flat spacetime of arbitrary odd dimension, then the retarded vector potential $A^μ$ generated by a point charge turns out to be pure gauge, $A^μ=\partial^μχ$. By Gauss' law, the charge shows up as zero. The classical electromagnetic coupling is thus missing from odd-dimensional worlds. If the action is augmented by the addition of the Chern--Simons term, then the classical interaction picture in the three-dimensional world becomes nontrivial.

hep-th

Inertial frames of reference, space and time measurements, and physical principles of special relativity revisited

We give a critical analysis of the conceptual foundations of special relativity. We formulate a simple operational criterion for distinguishing between noninertial and inertial frames which is introduced prior to geometry. We associate the concept of maximal velocity with the existence of an upper bound for a set of rates of movers which travel in the same direction. We define the standard scale for reading the time flow. We refine the treatment of both Einstein's postulates, the principle of relativity and constancy of the velocity of light. The proposed ``reconstruction'' of the geometry of Minkowski space will hopefully be useful for the ongoing examination of possible Lorentz violations.

gr-qc

Massless interacting particles

We show that classical electrodynamics of massless charged particles and the Yang--Mills theory of massless quarks do not experience rearranging their initial degrees of freedom into dressed particles and radiation. Massless particles do not radiate. We consider a version of the direct interparticle action theory for these systems following the general strategy of Wheeler and Feynman.

hep-th

Electromagnetic radiation in even-dimensional spacetimes

The basic concepts and mathematical constructions of the Maxwell--Lorentz electrodynamics in flat spacetime of an arbitrary even dimension $d=2n$ are briefly reviewed. We show that the retarded field strength ${\cal F}^{(2n)}_{μν}$ due to a point charge living in a $2n$-dimensional world can be algebraically expressed in terms of the retarded vector potentials ${\cal A}^{(2m)}_μ$ generated by this charge as if it were accommodated in $2m$-dimensional worlds nearby, $2\le m\le n+1$. With this finding, the rate of radiated energy-momentum of the electromagnetic field takes a compact form.

hep-th

Black holes: interfacing the classical and the quantum

The central idea advocated in this paper is that {forming the black hole horizon is attended with transition from the classical regime of evolution to the quantum one}. We justify the following criterion for discriminating between the classical and the quantum: {spontaneous creations and annihilations of particle-antiparticle pairs are impossible in the classical world but possible in the quantum world}. We show that it is sufficient to {change the overall sign of the spacetime signature in the classical picture of field propagation for it to be treated as its associated quantum picture}. To describe a self-gravitating object at the last stage of its classical evolution, we propose to use the Foldy--Wouthuysen representation of the Dirac equation in curved spacetimes, and the Gozzi classical path integral. In both approaches, maintaining the dynamics in the classical regime is controlled by supersymmetry.

gr-qc

Self-accelerated Universe

It is widely believed that the large redshifts for distant supernovae are explained by the vacuum energy dominance, or, in other words, by the cosmological constant in Einstein's equations, which is responsible for the anti-gravitation effect. A tacit assumption is that particles move along a geodesic for the background metric. This is in the same spirit as the consensus regarding the uniform Galilean motion of a free electron. However, there is a runaway solution to the Lorentz--Dirac equation governing the behavior of a radiating electron, in addition to the Galilean solution. Likewise, a runaway solution to the entire system of equations, both gravitation and matter equations of motion including, may provide an alternative explanation for the accelerated expansion of the Universe, without recourse to the hypothetic cosmological constant.

gr-qc

On inert properties of particles in classical theory

This is a critical review of inert properties of classical relativistic point objects. The objects are classified as Galilean and non-Galilean. Three types of non-Galilean objects are considered: spinning, rigid, and dressed particles. In the absence of external forces, such particles are capable of executing not only uniform motions along straight lines but also Zitterbewegungs, self-accelerations, self-decelerations, and uniformly accelerated motions. A free non-Galilean object possesses the four-velocity and the four-momentum which are in general not collinear, therefore, its inert properties are specified by two, rather than one, invariant quantities. It is shown that a spinning particle need not be a non-Galilean object. The necessity of a rigid mechanics for the construction of a consistent classical electrodynamics in spacetimes of dimension D+1 is justified for D+1>4. The problem of how much the form of fundamental laws of physics orders four dimensions of our world is revised together with its solution suggested by Ehrenfest. The present analysis made it apparent that the notion of the ``back-reaction'' does not reflect the heart of the matter in classical field theories with point-like sources, the notion of ``dressed'' particles proves more appropriate.

hep-th

Exact Solutions of Classical Electrodynamics and the Yang--Mills--Wong Theory in Even-Dimensional Spacetime

Exact solutions of classical gauge theories in even-dimensional (D=2n) spacetimes are discussed. Common and specific properties of these solutions are analyzed for the particular dimensions D=2, D=4, and D=6. A consistent formulation of classical gauge field theories with pointlike charged or colored particles is proposed for D=6. The particle Lagrangian must then depend on the acceleration. The self-interaction of a point particle is considered for D=2 and D=6. In D=2, radiation is absent and all processes are reversible. In D=6, the expression for the radiation rate and the equation of motion of a self-interacting particle are derived; from which follows that the Zitterbewegung always leads to radiation. It is shown that non-Abelian solutions are absent for any D not equal to 4; only Coulomb-like solutions, which correspond to the Abelian limit of the D-dimensional Yang--Mills--Wong theory, are admitted.

hep-th

Holography and two phases of the QCD vacuum

The holographic principle is often (and hastily) attributed to quantum gravity and domains of the Planck size. Meanwhile it can be usefully applied to problems where gravitation effects are negligible and domains of less exotic size. The essence of this principle is that any physical system can be taken to be either classical, placed in a D+1-dimensional spacetime, or quantum-mechanical, located in its D-dimensional boundary. For example, one believes that a hydrogen atom is a typical quantum system living in a four-dimensional spacetime, but it can also be conceived as a classical system living in a five-dimensional embracing spacetime. The subnuclear realm is more intricate since the gluon vacuum reveals two phases, the hadronic and plasma phases. They differ in energetics and symmetry. Moreover, the classical four-dimensional picture is pertinent to the behavior of constituent quarks while the plasma phase is expected to be grasped by standard four-dimensional QCD. The relation between the holographic standpoint and the symmetry treatment of these two phases is outlined. Exact retarded solutions to the classical SU(N) four-dimensional Yang-Mills equations with the source composed of several point-like colored particles is considered. Features of these solutions in the large-N limit provide insight into the gauge symmetries of two gluon vacua.

hep-th

Holography and the origin of anomalies

The holographic principle is represented as the well-known de Alfaro, Fubini and Furlan correspondence between the generating functional for the Green functions of the Euclidean quantum field theory in $D$ dimensions and the Gibbs average for the classical statistical mechanics in $D+1$ dimensions. This correspondence is used to explain the origin of quantum anomalies and the irreversibility in the classical theory. The holographic mapping of a classical string field theory onto a local quantum field theory is outlined.

hep-th