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We study Weyl structures on lightlikes hypersurfaces endowed with a conformal structure of certain type and specific screen distribution: the Weyl screen structures. We investigate various differential geometric properties of Einstein-Weyl…

Differential Geometry · Mathematics 2007-05-23 Cyriaque Atindogbe , Lionel Bérard Bergery

The goal of this paper is to develop the theory of Courant algebroids with integrable para-Hermitian vector bundle structures by invoking the theory of Lie bialgebroids. We consider the case where the underlying manifold has an almost…

Differential Geometry · Mathematics 2025-01-08 Aidan Patterson

We work in both the complex and in the para-complex categories and examine (para)-K\"ahler Weyl structures in both the geometric and in the algebraic settings. The higher dimensional setting is quite restrictive. We show that any…

Differential Geometry · Mathematics 2012-04-04 P. Gilkey , S. Nikcevic

Let M be a paracompact smooth manifold of dimension n; A a Weil algebra and M^A the Weil bundle associated. We define and describe the notion of \widetilded-Poisson cohomology and of \widetilded^A -Poisson cohomology on M^A.

Differential Geometry · Mathematics 2013-10-10 Vann Borhen Nkou , Basile Guy Richard Bossoto

The geometry of the Lie algebroid generalized tangent bundle of a generalized Lie algebroid is developed. Formulas of Ricci type and identities of Cartan and Bianchi type are presented. Introducing the notion of geodesic of a mechanical…

Differential Geometry · Mathematics 2014-12-16 C. M. Arcus , E. Peyghan , E. Sharahi

A Weyl structure is usually defined by an equivalence class of pairs $({\bf g}, \boldsymbol{\omega})$ related by Weyl transformations, which preserve the relation $\nabla {\bf g}=\boldsymbol{\omega}\otimes{\bf g}$, where ${\bf g}$ and…

General Relativity and Quantum Cosmology · Physics 2019-11-01 Adria Delhom , Iarley P. Lobo , Gonzalo J. Olmo , Carlos Romero

Starting from a real analytic surface $\mathcal{M}$ with a real analytic conformal Cartan connection A. Bor\'owka constructed a minitwistor space of an asymptotically hyperbolic Einstein-Weyl manifold with $\mathcal{M}$ being the boundary.…

Differential Geometry · Mathematics 2020-04-29 Rouzbeh Mohseni

We develop the properties of Weyl geometry, beginning with a review of the conformal properties of Riemannian spacetimes. Decomposition of the Riemann curvature into trace and traceless parts allows an easy proof that the Weyl curvature…

General Relativity and Quantum Cosmology · Physics 2018-06-19 James T. Wheeler

Degenerate submanifolds of pseudo-Riemannian manifolds are quite difficult to study because there is no prefered connection when the submanifold is not totally geodesic. For the particular case of degenerate totally umbilical hypersurfaces,…

Differential Geometry · Mathematics 2007-05-23 Cyriaque Atindogbe , Lionel Bérard Bergery

This is an expanded version of a series of lectures delivered at the 25th Winter School ``Geometry and Physics'' in Srni. After a short introduction to Cartan geometries and parabolic geometries, we give a detailed description of the…

Differential Geometry · Mathematics 2007-05-23 Andreas Cap

Motivated by an axiomatic approach to characterize space-time it is investigated a reformulation of Einstein's gravity where the pseudo-riemannian geometry is substituted by a Weyl one. It is presented the main properties of the Weyl…

General Relativity and Quantum Cosmology · Physics 2011-12-19 F. P. Poulis , J. M. Salim

An extension to higher dimensions of the Bel-Debever characterization of the Weyl tensor is considered. This provides algebraic conditions that uniquely determine the multiplicity of a Weyl aligned null direction (WAND), and thus the…

General Relativity and Quantum Cosmology · Physics 2009-10-02 Marcello Ortaggio

On a $3$D manifold, a Weyl geometry consists of pairs $(g, A) =$ (metric, $1$-form) modulo gauge $\widehat{g} = {\rm e}^{2\varphi} g$, $\widehat{A} = A + {\rm d}\varphi$. In 1943, Cartan showed that every solution to the Einstein-Weyl…

Differential Geometry · Mathematics 2020-06-18 Joël Merker , Paweł Nurowski

We study almost hypercomplex skew-Hermitian structures and almost quaternionic skew-Hermitian structures, as the geometric structures underlying $\mathsf{SO}^\ast(2n)$- and $\mathsf{SO}^\ast(2n)\mathsf{Sp}(1)$-structures, respectively. The…

Differential Geometry · Mathematics 2023-11-29 Ioannis Chrysikos , Jan Gregorovič , Henrik Winther

We provide an extension of the Gromov--Zimmer Embedding Theorem for Cartan geometries of [3] to tractor bundles carrying any invariant connection, including tractor connections and prolongation connections of first BGG operators for…

Differential Geometry · Mathematics 2025-10-14 Karin Melnick , Katharina Neusser

We reduce CR-structures on smooth elliptic and hyperbolic manifolds of CR-codimension 2 to parallelisms thus solving the problem of global equivalence for such manifolds. The parallelism that we construct is defined on a sequence of two…

Complex Variables · Mathematics 2007-05-23 V. V. Ezhov , A. V. Isaev , G. Schmalz

We show that on a surface locally every affine torsion-free connection is projectively equivalent to a Weyl connection. First, this is done using exterior differential system theory. Second, this is done by showing that the solutions of the…

Differential Geometry · Mathematics 2013-12-20 Thomas Mettler

We define the notion of Witt structure on the tangent bundle of a pseudo-Riemannian manifold and we introduce a connection adapted to a such structure. The notions of geodesics and symmetric spaces are revisited in this setting and…

Differential Geometry · Mathematics 2019-10-16 Robert Petit

We introduce and discuss (local) symmetries of geometric structures. These symmetries generalize the classical (locally) symmetric spaces to various other geometries. Our main tools are homogeneous Cartan geometries and their explicit…

Differential Geometry · Mathematics 2012-07-03 Jan Gregorovič

The conditions under which a given manifold $M$ may be given a tangent bundle or a cotangent bundle structure are analyzed. This is an important property arising in different contexts. For instance, in the study of integrability of a given…

Mathematical Physics · Physics 2026-01-26 José F. Cariñena , Jesús Clemente-Gallardo , Giuseppe Marmo