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We show that ``ergodic regime'' appears for generic dispersion relations in the semiclassical motion of electrons in a metal and we prove that, in the fixed energy picture, the measure of the set of such directions is zero.

Mathematical Physics · Physics 2007-05-23 Roberto De Leo

We study electromagnetic test fields in the background of vacuum black rings using Killing vectors as vector potentials. We consider both spacetimes with a rotating S^1 and with a rotating S^2 and we demonstrate, in particular, that the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Marcello Ortaggio , Vojtech Pravda

This paper initiates a series of works dedicated to the rigorous study of the precise structure of gravitational radiation near infinity. We begin with a brief review of an argument due to Christodoulou [1] stating that Penrose's proposal…

General Relativity and Quantum Cosmology · Physics 2025-08-20 Lionor M. A. Kehrberger

In this paper, we are eager to construct a new class of (n+1)-dimensional static magnetic brane solutions in quasi-topological gravity coupled to nonlinear electrodynamics such as exponential and logarithmic forms. The solutions of this…

General Physics · Physics 2019-06-19 A. Bazrafshan , F. Naeimipour , M. Ghanaatian , Gh. Forozani , A. Alizadeh

We propose a new relativistic Lorentz-invariant spin-noncommutative algebra. Using the Weyl ordering of noncommutative position operators, we build an analogue of the Moyal-Groenewald product for the proposed algebra. The Lagrange function…

High Energy Physics - Theory · Physics 2016-11-02 V. M. Vasyuta , V. M. Tkachuk

Electrostatic bender optics are derived up to second order (third order in fields and the Hamiltonian) and applied to the proposed EDM proton ring. The results for linear optics agree with those already presented by V.\ Lebedev (Nov.\ 18,…

Accelerator Physics · Physics 2015-08-04 R. Baartman

We construct an electromagnetic field whose scalar potential is a pulsed-beam wavelet Psi (an analytic continuation of a classical Huygens wavelet). The vector potential A is determined up to three complex parameters by requiring that (a)…

Mathematical Physics · Physics 2011-03-07 Gerald Kaiser

We identify, in spacetimes satisfying the null convergence condition, a certain natural class of null hypersurfaces that admit null sections with constant surface gravity. Our work is meant to offer complementary results to previous work on…

General Relativity and Quantum Cosmology · Physics 2023-08-22 Ivan P. Costa e Silva , José L. Flores , Benjamín Olea

The quantum null energy condition (QNEC) is a quantum generalization of the null energy condition which gives a lower bound on the null energy in terms of the second derivative of the von Neumann entropy or entanglement entropy of some…

High Energy Physics - Theory · Physics 2020-03-30 Taha A Malik , Rafael Lopez-Mobilia

In this letter we introduce a particular solution for parallel electric and magnetic fields, in a gravitational background, which satisfy free-wave equations and the phenomenology suggested by astrophysical plasma physics. These free-wave…

High Energy Physics - Theory · Physics 2009-11-11 E. M. C. Abreu , C. Pinheiro , S. A. Diniz , F. C. Khanna

Magneto-optical properties of the ferromagnetic semiconductor GaMnAs are studied in a material specific multi-band tight-binding approach. Two realistic models are compared: one has no impurity band while the other shows an impurity band…

Materials Science · Physics 2009-10-14 M. Turek , J. Siewert , J. Fabian

We characterise the integrability of any co-CR quaternionic structure in terms of the curvature and a generalized torsion of the connection. Also, we apply this result to obtain, for example, the following. (1) New co-CR quaternionic…

Differential Geometry · Mathematics 2013-05-17 Radu Pantilie

Searching normal forms for real analytic submanifolds of C^n involves convergence problems. In 1983, J.K. Moser and S.M. Webster provided examples of real analytic surfaces in C^2 having an isolated hyperbolic (in the sense of E. Bishop)…

Complex Variables · Mathematics 2007-05-23 Joël Merker

Magnetically uncharged, magnetic linear response of the vacuum filled with arbitrarily combined constant electric and magnetic fields to an imposed static electric charge is found within general nonlinear electrodynamics. When the electric…

High Energy Physics - Theory · Physics 2020-05-26 T. C. Adorno , D. M. Gitman , A. E. Shabad

The quantum dynamics of an electron in a uniform magnetic field is studied for geometries corresponding to integrable cases. We obtain the uniform asymptotic approximation of the WKB energies and wavefunctions for the semi-infinite plane…

Mesoscale and Nanoscale Physics · Physics 2009-10-30 D. Spehner , R. Narevich , E. Akkermans

We study exact solutions of nonlinear electrodynamics coupled to three-dimensional gravity with torsion. We show that in any static and spherically symmetric configuration, at least one component of the electromagnetic field has to vanish.…

General Relativity and Quantum Cosmology · Physics 2009-09-02 M. Blagojević , B. Cvetković , O. Misković

Electrical impedance tomography is an imaging modality for extracting information on the interior structure of a physical body from boundary measurements of current and voltage. This work studies a new robust way of modeling the contact…

Numerical Analysis · Mathematics 2022-07-06 J. Dardé , N. Hyvönen , T. Kuutela , T. Valkonen

An optical equation for null strings is derived. The equation is similar to Sachs' optical equations for null geodesic congruences. The string optical equation is given in terms of a single complex scalar function $Z$, which is a…

General Relativity and Quantum Cosmology · Physics 2021-06-16 Dmitri Fursaev

In this note, we investigate conformally flat submanifolds of Euclidean space with positive index of relative nullity. Let $M^n$ be a complete conformally flat manifold and let $f\colon M^n\to \R^m$ be an isometric immersion. We prove the…

Differential Geometry · Mathematics 2019-05-23 Christos-Raent Onti

We give new and rather general gluing theorems for anti-self-dual (ASD) conformal structures, following the method suggested by Floer. The main result is a gluing theorem for pairs of conformally ASD manifolds `joined' across a common piece…

Differential Geometry · Mathematics 2007-05-23 A. G. Kovalev , M. A. Singer