Birefringence induced by pp-wave modes in an electromagnetically active dynamic aether

In the framework of the Einstein-Maxwell-aether theory we study the birefringence effect, which can occur in the pp-wave symmetric dynamic aether. The dynamic aether is considered to be latently birefringent quasi-medium, which displays this hidden property if and only if the aether motion is non-uniform, i.e., when the aether flow is characterized by the non-vanishing expansion, shear, vorticity or acceleration. In accordance with the dynamo-optical scheme of description of the interaction between electromagnetic waves and the dynamic aether, we shall model the susceptibility tensors by the terms linear in the covariant derivative of the aether velocity four-vector. When the pp-wave modes appear in the dynamic aether, we deal with a gravitationally induced degeneracy removal with respect to hidden susceptibility parameters. As a consequence, the phase velocities of electromagnetic waves possessing orthogonal polarizations do not coincide, thus displaying the birefringence effect. Two electromagnetic field configurations are studied in detail: longitudinal and transversal with respect to the aether pp-wave front. For both cases the solutions are found, which reveal anomalies in the electromagnetic response on the action of the pp-wave aether mode.Comment: 13 pages, 0 figures, list of references is modified, misprints eliminate

Un método energético para calcular el uso de energía de combustibles fósiles

En el artículo se ha considerado un método energético para calcular el uso de energía de combustibles fósiles. En el mercado mundial, el precio del combustible depende de la oferta y la demanda y no implica costos de energía para la producción de combustible. Charles Hall, un científico estadounidense, sugirió un análisis energético de la actividad económica, quien introdujo una noción de energía devuelta sobre energía invertida, como una relación entre energía devuelta e invertida, en el discurso científico. No se ha tenido en cuenta la depreciación de la energía invertida en este método. Todas las pérdidas se incorporan por completo, cuando la relación entre la energía beneficiosa usada en todas las cadenas de flujo del proceso desde la exploración de depósitos de combustible hasta la utilización de energía, y la cantidad considerada de energía primaria de combustible natural se toma como el coeficiente de uso de beneficioso de energía primaria (CBPEU). Cuando se determina el CBPEU, se tienen en cuenta todas las pérdidas de energía potenciales; Se define el grado de depreciación de la energía contenida en el combustible, desde su depósito hasta el consumidor. Cuando se utiliza energía de fuentes renovables, un coeficiente de conversión de energía de fuentes renovables, definido como la relación entre la energía entregada por una unidad de potencia durante todo el período de operación y la energía invertida teniendo en cuenta el CBPEU durante el mismo período, representará un criterio objetivo. de eficiencia de la unidad de potenci

Neutrino scattering on polarized electron target as a test of neutrino magnetic moment

We suggest to use a polarized electron target for improving the sensitivity of the search for the neutrino magnetic moment to the level $\sim 3\cdot10^{-13}\mu_B$ in the processes of neutrino (antineutrino) -- electron scattering. It is shown that in this case the weak interaction term in the total cross section is significantly suppressed comparing with unpolarized case, but the electromagnetic term does not depend on electron polarization.Comment: 11 pages, LaTeX2e, using elsart.cls and epsf.sty, 3 postscript figures. Accepted in Phys. Lett.

Peculiarities of dynamics of Dirac fermions associated with zero-mass lines

Zero-mass lines result in appearance of linear dispersion modes for Dirac fermions. These modes play an important role in various physical systems. However, a Dirac fermion may not precisely follow a single zero-mass line, due to either tunneling between different lines or centrifugal forces. Being shifted from a zero-mass line the Dirac fermion acquires mass which can substantially influence its expected "massless" behavior. In the paper we calculate the energy gap caused by the tunneling between two zero-mass lines and show that its opening leads to the delocalization of linear dispersion modes. The adiabatic bending of a zero-mass line gives rise to geometric phases. These are the Berry phase, locally associated with a curvature, and a new phase resulting from the mass square asymmetry in the vicinity of a zero-mass line.Comment: 6 pages, 4 figures. In the second version some references were added and minor changes were made in the introductio