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Related papers: Discrete curvature

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We look at curvatures that are supported on k-dimensional parts of a simplicial complex G. These curvature all satisfy the Gauss-Bonnet theorem, provided that the k-dimensional simplices cover $G$. Each of these curvatures can be written as…

Combinatorics · Mathematics 2024-09-04 Oliver Knill

Duality principle for approximation of geometrical objects (also known as Eudoxus exhaustion method) was extended and perfected by Archimedes in his famous tractate "Measurement of circle". The main idea of the approximation method by…

Differential Geometry · Mathematics 2008-11-10 V. A. Garanzha

We illustrate connections between differential geometry on finite simple graphs G=(V,E) and Riemannian manifolds (M,g). The link is that curvature can be defined integral geometrically as an expectation in a probability space of…

Combinatorics · Mathematics 2019-12-25 Oliver Knill

We shall introduce the singular curvature function on cuspidal edges of surfaces, which is related to the Gauss-Bonnet formula and which characterizes the shape of cuspidal edges. Moreover, it is closely related to the behavior of the…

Differential Geometry · Mathematics 2007-05-23 Kentaro Saji , Masaaki Umehara , Kotaro Yamada

Motivated by a M\"obius invariant subdivision scheme for polygons, we study a curvature notion for discrete curves where the cross-ratio plays an important role in all our key definitions. Using a particular M\"obius invariant…

Differential Geometry · Mathematics 2020-09-01 Christian Müller , Amir Vaxman

Curvature is a fundamental geometric characteristic of smooth spaces. In recent years different notions of curvature have been developed for combinatorial discrete objects such as graphs. However, the connections between such discrete…

Probability · Mathematics 2023-11-09 Pim van der Hoorn , Gabor Lippner , Carlo Trugenberger , Dmitri Krioukov

Discrete analogs of extrema of curvature and generalizations of the four-vertex theorem to the case of polygons and polyhedra are suggested and developed. For smooth curves and polygonal lines in the plane, a formula relating the number of…

Metric Geometry · Mathematics 2010-07-16 Oleg R. Musin

We show how to define curvature as a measure using the Gauss-Bonnet Theorem on a family of singular surfaces obtained by gluing together smooth surfaces along boundary curves. We find an explicit formula for the curvature measure as a sum…

Classical Analysis and ODEs · Mathematics 2018-07-02 Robert S Strichartz

We use a Riemannnian approximation scheme to define a notion of $\textit{sub-Riemannian Gaussian curvature}$ for a Euclidean $C^{2}$-smooth surface in the Heisenberg group $\mathbb{H}$ away from characteristic points, and a notion of…

Differential Geometry · Mathematics 2016-04-04 Zoltán Balogh , Jeremy T. Tyson , Eugenio Vecchi

We study discrete curvatures computed from nets of curvature lines on a given smooth surface, and prove their uniform convergence to smooth principal curvatures. We provide explicit error bounds, with constants depending only on properties…

Differential Geometry · Mathematics 2015-05-07 Ulrich Bauer , Konrad Polthier , Max Wardetzky

In this paper, we study a natural discretization of the smooth Gaussian curvature on surfaces, which is defined as the quotient of the angle defect and the area of a geodesic disk at a vertex of a polyhedral surface. It is proved that each…

Differential Geometry · Mathematics 2023-09-14 Xu Xu , Chao Zheng

The problem of defining correctly geometric objects such as the curvature is a hard one in discrete geometry. In 2009, Ollivier defined a notion of curvature applicable to a wide category of measured metric spaces, in particular to graphs.…

Differential Geometry · Mathematics 2014-03-10 Benoît Loisel , Pascal Romon

Within a framework of noncommutative geometry, we develop an analogue of (pseudo) Riemannian geometry on finite and discrete sets. On a finite set, there is a counterpart of the continuum metric tensor with a simple geometric…

General Relativity and Quantum Cosmology · Physics 2009-10-31 A. Dimakis , F. Muller-Hoissen

A Clifford algebra model for M"obius geometry is presented. The notion of Ribaucour pairs of orthogonal systems in arbitrary dimensions is introduced, and the structure equations for adapted frames are derived. These equations are…

Differential Geometry · Mathematics 2007-05-23 Alexander I. Bobenko , Udo J. Hertrich-Jeromin

Many applications of geometry modeling and computer graphics necessite accurate curvature estimations of curves on the plane or on manifolds. In this paper, we define the notion of the discrete geodesic curvature of a geodesic polygon on a…

Numerical Analysis · Mathematics 2020-11-26 Aziz Ikemakhen , Mohamed Bellaihou

We propose a notion of discrete elastic and area-constrained elastic curves in 2-dimensional space forms. Our definition extends the well-known discrete Euclidean curvature equation to space forms and reflects various geometric properties…

Differential Geometry · Mathematics 2025-01-24 Tim Hoffmann , Jannik Steinmeier , Gudrun Szewieczek

We describe how to approximate the Riemann curvature tensor as well as sectional curvatures on possibly infinite-dimensional shape spaces that can be thought of as Riemannian manifolds. To this end, we extend the variational time…

Numerical Analysis · Mathematics 2019-12-17 Alexander Effland , Behrend Heeren , Martin Rumpf , Benedikt Wirth

We adopt a measure-theoretic perspective on the Riemannian approximation scheme proving a sub-Riemannian Gauss-Bonnet theorem for surfaces in 3D contact manifolds. We show that the zero-order term in the limit is a singular measure…

Differential Geometry · Mathematics 2025-10-01 Davide Barilari , Eugenio Bellini , Andrea Pinamonti

Seiberg-Witten theory leads to a delicate interplay between Riemannian geometry and smooth topology in dimension four. In particular, the scalar curvature of any metric must satisfy certain non-trivial estimates if the manifold in question…

Differential Geometry · Mathematics 2016-09-07 Claude LeBrun

In this paper we study "discrete polynomial blending," a term used to define a certain discretized version of curve blending whereby one approximates from the "sum of tensor product polynomial spaces" over certain grids. Our strategy is to…

Numerical Analysis · Mathematics 2017-04-28 Scott Kersey