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Related papers: Generalized metrics and generalized twistor spaces

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We find a worldsheet realization of generalized complex geometry, a notion introduced recently by Hitchin which interpolates between complex and symplectic manifolds. The two-dimensional model we construct is a supersymmetric relative of…

High Energy Physics - Theory · Physics 2009-11-10 Ulf Lindstrom , Ruben Minasian , Alessandro Tomasiello , Maxim Zabzine

The second fundamental form of Riemannian geometry is generalised to the case of a manifold with a linear connection and an integrable distribution. This bilinear form is generally not symmetric and its skew part is the torsion. The form…

Differential Geometry · Mathematics 2023-07-20 G. E. Prince

A generalized Stiefel manifold is the manifold of orthonormal frames in a vector space with a non-degenerated bilinear or hermitian form. In this article, the Isometry group of the generalized Stiefel manifolds are computed at least up to…

Differential Geometry · Mathematics 2019-05-22 Manuel Sedano-Mendoza

We explore a definition of uniformity on noncompact manifolds that does not require a Riemannian metric, but is equivalent to bounded gemetry. These are unfinished research notes (and will likely never be published), but since they were…

Differential Geometry · Mathematics 2024-07-25 Jaap Eldering

We compare three notions of genericity of separable metric structures. Our analysis provides a general model theoretic technique of showing that structures are generic in descriptive set theoretic (topological) sense and in measure…

Logic · Mathematics 2008-02-04 Alexander Usvyatsov

In this paper, we investigate the geometry of Einstein-type equation on a Riemannian manifold, unifying various particular geometric structures recently studied in the literature, such as critical point equation and vacuum static equation.…

Differential Geometry · Mathematics 2022-03-31 Gabjin Yun , Seungsu Hwang

We introduce the notion of a hamiltonian 2-form on a Kaehler manifold and obtain a complete local classification. This notion appears to play a pivotal role in several aspects of Kaehler geometry. In particular, on any Kaehler manifold with…

Differential Geometry · Mathematics 2007-05-23 Vestislav Apostolov , David M. J. Calderbank , Paul Gauduchon

Geometric torsions are torsions of acyclic complexes of vector spaces which consist of differentials of geometric quantities assigned to the elements of a manifold triangulation. We use geometric torsions to construct invariants for a…

Geometric Topology · Mathematics 2009-11-13 I. G. Korepanov

Let $X$ be a conical symplectic variety admitting a crepant resolution $Y$. Based on the theory of universal Poisson deformations, we construct a complex manifold called the principal twistor model associated with $Y$. We prove a…

Algebraic Geometry · Mathematics 2026-05-12 Ryota Kotani

In this paper, an approach for generalizing the Gromov-Hausdorff metric is presented, which applies to metric spaces equipped with some additional structure. A special case is the Gromov-Hausdorff-Prokhorov metric between measured metric…

Metric Geometry · Mathematics 2023-11-30 Ali Khezeli

Generalized tensor analysis in the sense of Colombeau's construction is employed to introduce a nonlinear distributional pseudo-Riemannian geometry. In particular, after deriving several characterizations of invertibility in the algebra of…

Functional Analysis · Mathematics 2007-05-23 Michael Kunzinger , Roland Steinbauer

We introduce a geometrical framework for double field theory in which generalized Riemann and torsion tensors are defined without reference to a particular basis. This invariant geometry provides a unifying framework for the frame-like and…

High Energy Physics - Theory · Physics 2015-06-12 Olaf Hohm , Barton Zwiebach

We introduce the notion of even Clifford structures on Riemannian manifolds, a framework generalizing almost Hermitian and quaternion-Hermitian geometries. We give the complete classification of manifolds carrying parallel even Clifford…

Differential Geometry · Mathematics 2019-01-08 Andrei Moroianu , Uwe Semmelmann

In models of emergent gravity the metric arises as the expectation value of some collective field. Usually, many different collective fields with appropriate tensor properties are candidates for a metric. Which collective field describes…

General Relativity and Quantum Cosmology · Physics 2015-06-04 C. Wetterich

We study metric spaces homeomorphic to a closed oriented manifold from both geometric and analytic perspectives. We show that such spaces (which are sometimes called metric manifolds) admit a non-trivial integral current without boundary,…

Metric Geometry · Mathematics 2023-09-25 Giuliano Basso , Denis Marti , Stefan Wenger

This is a survey of old and new results on the problem when a compatible almost complex structure on a Riemannian manifold is a harmonic section or a harmonic map from the manifold into its twistor space. In this context, a special…

Differential Geometry · Mathematics 2016-11-18 Johann Davidov

The concept of closed trapped surface is of paramount importance in General Relativity and other gravitational theories. However, it is a purely geometrical object. With the aim of bringing this concept to closer attention by the…

Differential Geometry · Mathematics 2007-05-23 José M M Senovilla

We develop a Morse-Lusternik-Schnirelmann theory for the distance between two points of a smoothly embedded circle in a complete Riemannian manifold. This theory suggests very naturally a definition of width that generalises the classical…

Differential Geometry · Mathematics 2025-03-27 Lucas Ambrozio , Rafael Montezuma , Roney Santos

In earlier work we have shown that for certain geometric structures on a smooth manifold $M$ of dimension $n$, one obtains an almost para-K\"ahler--Einstein metric on a manifold $A$ of dimension $2n$ associated to the structure on $M$. The…

Differential Geometry · Mathematics 2024-09-17 Andreas Cap , Thomas Mettler

In this paper a bijective correspondence between superminimal surfaces of an oriented Riemannian $4$-manifold and particular Lagrangian submanifolds of the twistor space over the $4$-manifold is proven. More explicitly, for every…

Differential Geometry · Mathematics 2020-01-22 Reinier Storm