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The usual interpretation of Weyl geometry is modified in two senses. First, both the additive Weyl connection and its variation are treated as (1, 2) tensors under the action of Weyl covariant derivative. Second, a modified covariant…

General Relativity and Quantum Cosmology · Physics 2013-09-18 Fang-Fang Yuan , Yong-Chang Huang

Tangent categories provide an axiomatic approach to key structural aspects of differential geometry that exist not only in the classical category of smooth manifolds but also in algebraic geometry, homological algebra, computer science, and…

Differential Geometry · Mathematics 2018-08-29 Rory B. B. Lucyshyn-Wright

Let $(M, g)$ be a compact real analytic Riemannian manifold and $\pi \colon \widetilde{M} \to M$ its universal cover. Assume that $\widetilde{M}$ can be realised as a manifold definable in an o-minimal structure $\Sigma$ expanding…

Differential Geometry · Mathematics 2024-01-17 Vasily Rogov

We study the geometric properties of holomorphic distributions of totally null $m$-planes on a $(2m+\epsilon)$-dimensional complex Riemannian manifold $(\mathcal{M}, \bm{g})$, where $\epsilon \in {0,1}$ and $m \geq 2$. In particular, given…

Differential Geometry · Mathematics 2012-03-13 Arman Taghavi-Chabert

There are studied in details 5-dimensional pseudo-Riemannian manifolds equipped with the structure analogous to the almost cosymplectic (almost coKaehler) structure. The curvature by assumption commutes with the structure affinor and all…

Differential Geometry · Mathematics 2013-08-30 Piotr Dacko

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

The Weyl semimetals [1-6] are three-dimensional (3D) gapless topological phases with Weyl cones in the bulk band, and host massless quasiparticles known as Weyl fermions which were theorized by Hermann Weyl in the last twenties [7]. The…

Manifold learning is a fundamental task at the core of data analysis and visualisation. It aims to capture the simple underlying structure of complex high-dimensional data by preserving pairwise dissimilarities in low-dimensional…

Machine Learning · Computer Science 2026-03-13 Thomas Dagès , Simon Weber , Daniel Cremers , Ron Kimmel

In a neighborhood of a (positive definite) Riemannian space in which special, semigeodesic, coordinates are given, the metric tensor can be calculated from its values on a suitable hypersurface and some of components of the curvature tensor…

Differential Geometry · Mathematics 2010-06-17 J. Mikeš , A. Vanžurová

In the literature different concepts of compatibility between a projective structure and a conformal structure on a differentiable manifold are used. In particular compatibility in the sense of Weyl geometry is slightly more general than…

Differential Geometry · Mathematics 2020-07-31 Vladimir S. Matveev , Erhard Scholz

We describe two extensions of the notion of a self-dual connection in a vector bundle over a manifold M from dim M=4 to higher dimensions. The first extension, Omega-self-duality, is based on the existence of an appropriate 4-form Omega on…

High Energy Physics - Theory · Physics 2007-05-23 Dmitri V. Alekseevsky , Vicente Cortés , Chandrashekar Devchand

Representations on the Symmetric Positive Definite (SPD) manifold have garnered significant attention across different applications. In contrast, the manifold of full-rank correlation matrices, a normalized alternative to SPD matrices,…

Machine Learning · Computer Science 2026-05-20 Ziheng Chen , Xiaojun Wu , Bernhard Schölkopf , Nicu Sebe

Linear connections satisfying the Einstein metricity condition are important in the study of generalized Riemannian manifolds $(M,G=g+F)$, where the symmetric part $g$ of $G$ is a non-degenerate $(0,2)$-tensor, and $F$ is the skew-symmetric…

Differential Geometry · Mathematics 2025-08-12 Milan Zlatanović , Vladimir Rovenski

The generalized partially linear models on Riemannian manifolds are introduced. These models, like ordinary generalized linear models, are a generalization of partially linear models on Riemannian manifolds that allow for response variables…

Methodology · Statistics 2018-03-09 Amelia Simó , M. Victoria Ibáñez , Irene Epifanio , Vicent Gimeno

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

Weyl points are the simplest topologically-protected degeneracy in a three-dimensional dispersion relation. The realization of Weyl semimetals in photonic crystals has allowed these singularities and their consequences to be explored with…

Mesoscale and Nanoscale Physics · Physics 2020-11-23 R. L. Mc Guinness , P. R. Eastham

BGG resolutions and generalized BGG resolutions from representation theory of semisimple Lie algebras have been generalized to sequences of invariant differential operators on manifolds endowed with a geometric structure belonging to the…

Differential Geometry · Mathematics 2026-02-26 Andreas Cap

We study ECS manifolds, that is, pseudo-Riemannian manifolds with parallel Weyl tensor which are neither conformally flat nor locally symmetric. Every ECS manifold has rank 1 or 2, the rank being the dimension of a distinguished null…

Differential Geometry · Mathematics 2023-11-06 Andrzej Derdzinski , Ivo Terek

The superconducting s-wave state in Weyl semimetals in a strong strain-induced pseudomagnetic field is investigated in a model with local four-fermion interaction. It is found that only the inter-node pairing is possible in the lowest…

Superconductivity · Physics 2020-08-03 P. O. Sukhachov , E. V. Gorbar

This article is devoted to the study of self-distributive algebraic structures: algebras, bialgebras; additional structures on them, relations of these structures with Hopf algebras, Lie algebras, Leibnitz algebras etc. The basic example of…

Rings and Algebras · Mathematics 2025-05-15 Valeriy G. Bardakov , Tatiana A. Kozlovskaya , Dmitry V. Talalaev