23 research outputs found
Hawking Radiation as Quantum Tunneling in Rindler Coordinate
We substantiate the Hawking radiation as quantum tunneling of fields or
particles crossing the horizon by using the Rindler coordinate. The thermal
spectrum detected by an accelerated particle is interpreted as quantum
tunneling in the Rindler spacetime. Representing the spacetime near the horizon
locally as a Rindler spacetime, we find the emission rate by tunneling, which
is expressed as a contour integral and gives the correct Boltzmann factor. We
apply the method to non-extremal black holes such as a Schwarzschild black
hole, a non-extremal Reissner-Nordstr\"{o}m black hole, a charged Kerr black
hole, de Sitter space, and a Schwarzschild-anti de Sitter black hole.Comment: LaTex 19 pages, no figure; references added and replaced by the
version accepted in JHE
Theories of Low-Energy Quasi-Particle States in Disordered d-Wave Superconductors
The physics of low-energy quasi-particle excitations in disordered d-wave
superconductors is a subject of ongoing intensive research. Over the last
decade, a variety of conceptually and methodologically different approaches to
the problem have been developed. Unfortunately, many of these theories
contradict each other, and the current literature displays a lack of consensus
on even the most basic physical observables. Adopting a symmetry-oriented
approach, the present paper attempts to identify the origin of the disagreement
between various previous approaches, and to develop a coherent theoretical
description of the different low-energy regimes realized in weakly disordered
d-wave superconductors. We show that, depending on the presence or absence of
time-reversal invariance and the microscopic nature of the impurities, the
system falls into one of four different symmetry classes. By employing a
field-theoretical formalism, we derive effective descriptions of these
universal regimes as descendants of a common parent field theory of
Wess-Zumino-Novikov-Witten type. As well as describing the properties of each
universal regime, we analyse a number of physically relevant crossover
scenarios, and discuss reasons for the disagreement between previous results.
We also touch upon other aspects of the phenomenology of the d-wave
superconductor such as quasi-particle localization properties, the spin quantum
Hall effect, and the quasi-particle physics of the disordered vortex lattice.Comment: 42 Pages, 8 postscript figures, published version with updated
reference
Implicit Differense Scheme for Solution of Maxwell's Equations
Abstract:
The present paper is devoted to the description of numerical approach of solution problem Koshi for systems of Maxwell's equations in usual time. The implicit difference scheme used for approximation of Maxwell's equations with various boundary conditions is described.
Mathematical algorithms of the decision of system of the equations arising at use the implicit scheme are considered.Note:
Research direction:Mathematical problems and theory of numerical method