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Yu. A. Sitenko

Publications and source records attributed to Yu. A. Sitenko.

46 records · Page 3Linked to original sources
arXiv1998

Effects of Boson-Vacuum Polarization by a Singular Magnetic Vortex

In a space of arbitrary dimensions, the effect of an external magnetic field on the vacuum of a quantized charged scalar field is studied for the field configuration in the form of a singular vortex. The zeta-function technique is used to regularize ultraviolet divergences. The expression for the effective action is derived. It is shown that the energy density and current induced in the vacuum decrease exponentially at large distances from the vortex. The analytic properties of vacuum features as functions of the complex-valued space dimension are discussed.

hep-th↗
arXiv1998

Statistical Aspects of Neveu and Schwarz Dual Model

Statistical method is applied to Neveu and Schwartz model for obtaining the average characteristics of the heavy resonances: spin distribution, decay widths etc. The properties of the dual model spectrum of states constructed of both commuting and anticommuting operators are considered. In this case the spin characteristics coincide with the results of the statistical bootstrap model.

hep-th↗
arXiv1998

Vacuum Energy Induced by an External Magnetic Field in a Curved Space

The asymptotic expansion of the product of an operator raised to an arbitrary power and an exponential function of this operator is obtained. With the aid of this expansion, the density of vacuum energy induced by a static external magnetic field of an Abelian or non-Abelian nature is expressed in terms of the DeWitt-Seeley-Gilkey coefficients.

hep-th↗
arXiv1998

Quantum Numbers of the Theta Vacuum in (2+1)-Dimensional Spinor Electrodynamics: Charge and Magnetic Flux

A singular configuration of an external static vector field in the form of a magnetic string polarizes the vacuum of a second-quantized theory on the plane orthogonal to the string axis. The most general boundary conditions at the punctured singular point that are compatible with the self-adjointness of two-dimensional Dirac Hamiltonian are considered. The dependences of the induced vacuum quantum numbers on the parameter of the self-adjoint extension, on the string flux, and on the choice of irreducible representation of the matrices in (2+1)-dimensional spacetime are disscussed.

hep-th↗
arXiv1998

Induced Angular Momentum in (2+1)-Dimensional Spinor Electrodynamics in Curved Space

Effects due to fermion-vacuum polarization by an external static magnetic field are considered in a two-dimensional noncompact curved space with a nontrivial topology. An expression for the vacuun angular momentum is obtained. Like the vacuum fermion number, it proves to be dependent on the global characteristics of the field and space.

hep-th↗
arXiv1997

The Casimir-Aharonov-Bohm effect?

The combined effect of the magnetic field background in the form of a singular vortex and the Dirichlet boundary condition at the location of the vortex on the vacuum of quantized scalar field is studied. We find the induced vacuum energy density and current to be periodic functions of the vortex flux and holomorphic functions of the space dimension.

hep-th↗
arXiv1997

Self-Adjointness and Polarization of the Fermionic Vacuum in the Background of Nontrivial Topology

Singular configuration of an external static magnetic field in the form of a string polarizes vacuum in the secondly quantized theory on a plane which is orthogonal to the string axis. We consider the most general boundary conditions at the punctured singular point, which are compatible with the self-adjointness of the two-dimensional Dirac Hamiltonian. The dependence of the induced vacuum quantum numbers on the self-adjoint extension parameter and the flux of the string is determined.

hep-th↗
arXiv1997

Nonlocality, Self-Adjointness and Theta-Vacuum in Quantum Field Theory in Spaces with Nontrivial Topology

We consider an analogue of the Aharonov-Bohm effect in quantum field theory: the fermionic vacuum attains nontrivial quantum numbers in the background of a magnetic vortex even in the case when the spatial region of nonvanishing external field strength is excluded. The dependence of the vacuum quantum numbers on the value of the vortex flux and the choice of the condition on the boundary of the excluded region is determined.

hep-th↗
arXiv1996

Self-Adjointness of the Dirac Hamiltonian and Fermion Number Fractionization in the Background of a Singular Magnetic Vortex

The method of self-adjoint extensions is employed to determine the vacuum quantum numbers induced by a singular static magnetic vortex in $2+1$-dimensional spinor electrodynamics. The results obtained are gauge-invariant and, for certain values of the extension parameter, both periodic in the value of the vortex flux and possessing definite parity with respect to the charge conjugation.

hep-th↗