4 research outputs found
Non-perturbative Euler-Heisenberg Lagrangian and Paraelectricity in Magnetized Massless QED
In this paper we calculate the non-perturbative Euler-Heisenberg Lagrangian
for massless QED in a strong magnetic field , where the breaking of the
chiral symmetry is dynamically catalyzed by the external magnetic field via the
formation of an electro-positron condensate. This chiral condensate leads to
the generation of dynamical parameters that have to be found as solutions of
non-perturbative Schwinger-Dyson equations. Since the electron-positron pairing
mechanism leading to the breaking of the chiral symmetry is mainly dominated by
the contributions from the infrared region of momenta much smaller than
, the magnetic field introduces a dynamical ultraviolet cutoff in
the theory that also enters in the non-perturbative Euler-Heisenberg action.
Using this action, we show that the system exhibits a significant
paraelectricity in the direction parallel to the magnetic field. The
nonperturbative nature of this effect is reflected in the non-analytic
dependence of the obtained electric susceptibility on the fine-structure
constant. The strong paraelectricity in the field direction is linked to the
orientation of the electric dipole moments of the pairs that form the chiral
condensate. The large electric susceptibility can be used to detect the
realization of the magnetic catalysis of chiral symmetry breaking in physical
systems.Comment: 18 pages, to be published in NP
Magnetoelectric Effect in Strongly Magnetized Color Superconductivity
The effect of a strong magnetic field on the electric polarization of a
three-flavor color superconducting medium is investigated. We found that the
electric susceptibility of this strongly magnetized medium is highly
anisotropic. In the direction transverse to the applied magnetic field the
susceptibility reduces to that of the vacuum, while in the longitudinal
direction it depends on the magnetic field and decreases with it. The nature of
this behavior is associated with the field's dependence of the Cooper pairs'
coherence length, which plays the role of the electric dipole length. The
field's dependence of the electric polarization is interpreted as the
realization of the magnetoelectric effect in cold-dense quark matter.Comment: 10 pages, 1 figur
Electromagnetic radiation security estimation on the residential building roof for cellular antenna
The work objective is to estimate the electromagnetic environment on the roof where a mobile system base station aerial is installed. The problem arises during maintenance, repair, and assembly operations for antenna-feeder devices. The evaluation problem for ecological assessment of the electromagnetic environment at a standard height of two meters above the roof is solved with the computational prediction method. Two strict models are used for electrodynamic simulation of energy flux density, i.e. a two ray model which describes the plane electromagnetic wave diffraction on the flat perfectly conducting roof surface, and finite models of the roof are described with the canonical problem on a wedge of infinite extent. The difference between the developed model and the known ones lies within the research possibility not only in the computational points but within a whole computational plane. In the simulation process, antenna emission characteristics can be set in a number of ways including those obtained from the radiation object specifications, as it is proposed in a well-known technique. The simulation results for energy flux density distribution in a horizontal plane within the roof space are given. Computational points are placed at the square grid nodes with the period of a quarter wavelength of the transmitter. A physical interpretation of the obtained results is given. A safety conclusion on the human presence on the roof with operating directional cel lular antenna of GSM standard is formulated