English
Related papers

Related papers: Tensor tomography and frame flow ergodicity for ma…

200 papers

This paper explores the behavior of the torsional rigidity of a precompact domain as the ambient manifold evolves under a geometric flow. Specifically, we derive bounds on torsional rigidity under the Ricci Flow for Heisenberg spaces and…

Differential Geometry · Mathematics 2026-03-31 Vicent Gimeno i Garcia , Fernán González-Ibáñez

We derive a new formulation of the fully general relativistic equations describing a stationary equatorial MHD outflow from a rotating central object. The wind solution appears as a level contour of a `Bernoulli' function fixed by the…

Astrophysics · Physics 2016-08-30 F. Daigne , G. Drenkhahn

The problem of reconstruction of a flow of conducting incompressible fluid generating a given magnetic mode is considered. We use the magnetic induction equation to derive ordinary differential equations along the magnetic field lines,…

Chaotic Dynamics · Physics 2015-05-13 V. Zheligovsky

In this paper, we give a new lower bound for the eigenvalues of the Dirac operator on a compact spin manifold. This estimate is motivated by the fact that in its limiting case a skew-symmetric tensor (see Equation \eqref{eq:16}) appears…

Differential Geometry · Mathematics 2009-11-13 Georges Habib

Geometrical tools, used in Einstein's general relativity (GR), are applied to dynamo theory, in order to obtain fast dynamo action bounds to magnetic energy, from Killing symmetries in Ricci flows. Magnetic field is shown to be the shear…

Mathematical Physics · Physics 2009-05-12 Garcia de Andrade

We study geodesics flows on curved quantum Riemannian geometries using a recent formulation in terms of bimodule connections and completely positive maps. We complete this formalism with a canonical $*$ operation on noncommutative vector…

Quantum Algebra · Mathematics 2023-07-12 Edwin Beggs , Shahn Majid

Wedge-shaped geometries in low-Reynolds-number flows are of increasing importance, for instance, in the design of microfluidic devices. The corresponding Green's functions describing the induced flow in response to a locally applied force…

Our results concern geometry of a manifold endowed with a pair of complementary orthogonal distributions (plane fields) and a time-dependent Riemannian metric. The work begins with formulae concerning deformations of geometric quantities as…

Differential Geometry · Mathematics 2015-12-31 Vladimir Rovenski , Robert Wolak

We study deformations of Riemannian metrics on a given manifold equipped with a codimension-one foliation subject to quantities expressed in terms of its second fundamental form. We prove the local existence and uniqueness theorem and…

Differential Geometry · Mathematics 2011-08-16 Vladimir Rovenski , Pawel Walczak

Utilizing the covariant formulation of Penrose's plane wave limit by Blau et~al., we construct for any semi-Riemannian metric $g$ a family of "plane wave limits." These limits are taken along any geodesic of $g$, yield simpler metrics of…

Differential Geometry · Mathematics 2025-04-30 Amir Babak Aazami

We describe a scenario for the sunspot magnetic field topology that may account for recent observations of upflows and downflows in penumbrae. According to our conjecture, short narrow magnetic loops fill the penumbral volume. Flows along…

Astrophysics · Physics 2008-11-27 J. Sanchez Almeida

We prove that for the frame flow on a negatively curved, closed manifold of odd dimension other than 7, and a Holder continuous potential that is constant on fibers, there is a unique equilibrium measure. We prove a similar result for…

Dynamical Systems · Mathematics 2016-09-28 Ralf Spatzier , Daniel Visscher

In this paper, we first investigate the integral curvature condition to extend the mean curvature flow of submanifolds in a Riemannian manifold with codimension $d\geq1$, which generalizes the extension theorem for the mean curvature flow…

Differential Geometry · Mathematics 2011-04-07 Kefeng Liu , Hongwei Xu , Fei Ye , Entao Zhao

The vortex dynamics of uniaxial anisotropic superconductors in magnetic fields applied with arbitrary orientation is theoretically studied. Focus is on the model for electrical transport experiments in the linear regime. Relevant vortex…

Superconductivity · Physics 2012-11-15 N. Pompeo

The evolution of the magnetic helicity tensor for a nonzero mean magnetic field and for large magnetic Reynolds numbers in an anisotropic turbulence is studied. It is shown that the isotropic and anisotropic parts of the magnetic helicity…

Astrophysics · Physics 2008-11-26 N. Kleeorin , I. Rogachevskii

We study a gradient flow on Sobolev diffeomorphisms for the problem of image registration. The energy functional quantifies the effect of transforming a template to a target, while also penalizing deformation of the metric tensor. The main…

Differential Geometry · Mathematics 2025-08-12 Tracey Balehowsky , Carl-Joar Karlsson , Klas Modin

A new approach to analyze the properties of the energy-momentum tensor $T(z)$ of conformal field theories on generic Riemann surfaces (RS) is proposed. $T(z)$ is decomposed into $N$ components with different monodromy properties, where $N$…

High Energy Physics - Theory · Physics 2014-11-18 Franco Ferrari , Jan T. Sobczyk

A covariant reformulation of General Relativity is briefly considered from three points of view: geometrodynamics, Lagrange-Euler field theory, and gauge field theory. From a geometrodynamics perspective, a definition of the reference frame…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Alexander Poltorak

Let $(M,g,J)$ be a closed K\"ahler manifold with negative sectional curvature and complex dimension $m := \dim_{\mathbb{C}} M \geq 2$. In this article, we study the unitary frame flow, that is, the restriction of the frame flow to the…

Dynamical Systems · Mathematics 2024-12-25 Mihajlo Cekić , Thibault Lefeuvre , Andrei Moroianu , Uwe Semmelmann

By using variational calculus and exterior derivative formalism, we proposed in two previous joint papers with S. Siparov a new geometric approach for electromagnetism in pseudo-Finsler spaces. In the present paper, we provide more details,…

Mathematical Physics · Physics 2011-11-15 Nicoleta Voicu