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Related papers: Einstein-Weyl structures on lightike hypersurfaces

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An affine hypersurface (AH) structure is a pair comprising a conformal structure and a projective structure such that for any torsion-free connection representing the projective structure the completely trace-free part of the covariant…

Differential Geometry · Mathematics 2017-05-03 Daniel J. F. Fox

We consider four (real or complex) dimensional hyper-K\"ahler metrics with a conformal symmetry K. The three-dimensional space of orbits of K is shown to have an Einstein-Weyl structure which admits a shear-free geodesics congruence for…

Differential Geometry · Mathematics 2007-05-23 Maciej Dunajski , Paul Tod

Abundant second-order maximally conformally superintegrable Hamiltonian systems are re-examined, revealing their underlying natural Weyl structure and offering a clearer geometric context for the study of St\"ackel transformations (also…

Differential Geometry · Mathematics 2025-07-24 Andreas Vollmer

The authors study the geometry of lightlike hypersurfaces on manifolds $(M, c)$ endowed with a pseudoconformal structure $c = CO (n - 1, 1)$ of Lorentzian signature. Such hypersurfaces are of interest in general relativity since they can be…

Differential Geometry · Mathematics 2007-05-23 Maks A. Akivis , Vladislav V. Goldberg

We show uniqueness up to sign of positive, orthogonal almost-Kaehler structures on any non-scalar flat Kaehler-Einstein surface.

Differential Geometry · Mathematics 2012-08-09 A. J. diScala , Paul-Andi Nagy

Using a combination of techniques from conformal and complex geometry, we show the potentialization of 4-dimensional closed Einstein-Weyl structures which are half-algebraically special and admit a "half-integrable" almost-complex…

General Relativity and Quantum Cosmology · Physics 2021-10-13 Bernardo Araneda

Motivated by the study of Weyl structures on conformal manifolds admitting parallel weightless forms, we define the notion of conformal product of conformal structures and study its basic properties. We obtain a classification of Weyl…

Differential Geometry · Mathematics 2019-01-08 Florin Belgun , Andrei Moroianu

We find explicit examples of compact minitwistor spaces of genus one, whose Einstein-Weyl spaces have a connected component that is diffeomorphic to the de Sitter space. The induced Einstein-Weyl structure on it is Lorenzian, real-analytic,…

Differential Geometry · Mathematics 2024-12-16 Nobuhiro Honda , Fuminori Nakata

A conformal Lie group is a conformal manifold $(M,c)$ such that $M$ has a Lie group structure and $c$ is the conformal structure defined by a left-invariant metric $g$ on $M$. We study Weyl-Einstein structures on conformal solvable Lie…

Differential Geometry · Mathematics 2023-05-02 Viviana del Barco , Andrei Moroianu , Arthur Schichl

We find the local form of all non-closed Lorentzian Weyl manifolds $(M,c,\nabla)$ with recurrent curvature tensor.If the dimension of the manifold is greater than 3, then the conformal structure is flat, and the recurrent Weyl structure is…

Differential Geometry · Mathematics 2024-08-15 Andrei Dikarev , Anton S. Galaev , Eivind Schneider

We introduce the concept of a Clifford-Weyl structure on a conformal manifold, which consists of an even Clifford structure parallel with respect to the tensor product of a metric connection on the Clifford bundle and a Weyl structure on…

Differential Geometry · Mathematics 2019-01-08 Charles Hadfield , Andrei Moroianu

Weyl fermions are massless chiral quasiparticles existing in materials known as Weyl semimetals. Topological surface states, associated with the unusual electronic structure in the Weyl semimetals, have been recently demonstrated in linear…

Optics · Physics 2018-04-18 Ce Shang , Yuanlin Zheng , Boris A. Malomed

First, we show that a warped product of a line and a fiber manifold is weakly conformally flat and quasi Einstein if and only if the fiber is Einstein. Next, we characterize and classify contact (in particular, $K$-contact) Riemannian…

Differential Geometry · Mathematics 2022-12-02 Ramesh Sharma

A Weyl structure on a Riemannian manifold $(M,g)$ is a torsion-free linear connection $\nabla$ such that there is a $1$-form $\theta$ (called the Lee form) satisfying $\nabla g = 2\, \theta \otimes g$. We examine the case in which there…

Differential Geometry · Mathematics 2026-03-27 José Luis Carmona Jiménez

We construct a compact minitwistor space from a hyperelliptic curve with real structure and show that it yields a lot of new Lorentzian Einstein-Weyl spaces all of which are diffeomorphic to the 3-dimensional deSitter space. These…

Differential Geometry · Mathematics 2025-02-18 Nobuhiro Honda

We show that conformally compact, globally hyperbolic, Lorentzian Einstein-Weyl 3-manifolds are in natural one-to-one correspondence with orientation-reversing diffeomorphisms of the 2-sphere. The proof hinges on a holomorphic-disk analog…

Differential Geometry · Mathematics 2008-07-25 Claude LeBrun , L. J. Mason

In a previous paper, we presented new results on non-Riemannian geometry. For an asymmetric connection, we showed that a projective change in the symmetric part generates a vector field that is not arbitrary, but is the gradient of a…

General Physics · Physics 2018-07-25 A. C. V. V. de Siqueira

The problem of characterizing conformally Einstein manifolds by tensorial conditions has been tackled recently in papers by M. Listing, and in work by A. R. Gover and P. Nurowski. Their results apply to metrics satisfying a "non-degeneracy"…

Differential Geometry · Mathematics 2007-05-23 Jesse Alt

We prove trapped-surface formation for the Einstein-Weyl spinor system (gravity coupled to a massless left-handed two-spinor) without any symmetry assumption. To this end we establish a semi-global solution under double null foliation and…

General Relativity and Quantum Cosmology · Physics 2025-09-19 Peng Zhao , Xiaoning Wu

Lightlike Cartan geometries are introduced as Cartan geometries modelled on the future lightlike cone in Lorentz-Minkowski spacetime. Then, we provide an approach to the study of lightlike manifolds from this point of view. It is stated…

Differential Geometry · Mathematics 2020-03-24 Francisco J. Palomo