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Using a semi-symmetric metric connection, we construct Frenet frame and curvatures of curves in 3-dimensional manifolds and give examples of semi-symmetric Frenet curves in Euclidean, Sasakian and Kenmotsu manifolds.

Differential Geometry · Mathematics 2026-01-05 Şaban Güvenç

We introduce a class of half lightlike submanifolds of almost contact B-metric manifolds and prove that such submanifolds are semi-Riemannian with respect to the associated B-metric. Object of investigations are also minimal of the…

Differential Geometry · Mathematics 2020-03-17 Galia Nakova

Computing the Fr\'echet distance between two polygonal curves takes roughly quadratic time. In this paper, we show that for a special class of curves the Fr\'echet distance computations become easier. Let $P$ and $Q$ be two polygonal curves…

Computational Geometry · Computer Science 2019-08-28 Joachim Gudmundsson , Majid Mirzanezhad , Ali Mohades , Carola Wenk

We use geometric measure theory to introduce the notion of asymptotic cones associated with a singular subspace of a Riemannian manifold. This extends the classical notion of asymptotic directions usually defined on smooth submanifolds. We…

Differential Geometry · Mathematics 2015-01-13 Xiang Sun , Jean-Marie Morvan

How much of the combinatorial structure of a pointed polyhedron is contained in its vertex-facet incidences? Not too much, in general, as we demonstrate by examples. However, one can tell from the incidence data whether the polyhedron is…

Combinatorics · Mathematics 2007-05-23 Michael Joswig , Volker Kaibel , Marc E. Pfetsch , Guenter M. Ziegler

We obtain a coarse relationship between geometric intersection numbers of curves and the sum of their subsurface projection distances with explicit quasi-constants. By using this relationship, we give applications in the studies of the…

Geometric Topology · Mathematics 2017-09-12 Yohsuke Watanabe

For polyhedral convex cones in ${\mathbb R}^d$, we give a proof for the conic kinematic formula for conic curvature measures, which avoids the use of characterization theorems. For the random cones defined as typical cones of an isotropic…

Metric Geometry · Mathematics 2017-06-13 Rolf Schneider

For all $n,\phi\in \mathbb{N}$ with $\phi\geqslant n+1$, the smallest possible isoperimetric quotient of an $n$-dimensional convex polytope that has $\phi$ facets is shown to be bounded from above and from below by positive universal…

Metric Geometry · Mathematics 2025-09-18 Keith Ball , Károly J. Böröczky , Assaf Naor

This paper develops asymptotic methods to count faces of random high-dimensional polytopes. Beyond its intrinsic interest, our conclusions have surprising implications - in statistics, probability, information theory, and signal processing…

Metric Geometry · Mathematics 2007-06-13 David L. Donoho , Jared Tanner

The intersection of an affine subspace with the cone of positive semidefinite matrices is called a spectrahedron. An orthogonal projection thereof is called a spectrahedral shadow or projected spectrahedron. Spectrahedra and their…

Optimization and Control · Mathematics 2023-05-04 Daniel Dörfler , Andreas Löhne

Polygons are described as almost-convex if their perimeter differs from the perimeter of their minimum bounding rectangle by twice their `concavity index', $m$. Such polygons are called \emph{$m$-convex} polygons and are characterised by…

Combinatorics · Mathematics 2007-10-26 W. R. G. James , I. Jensen , A. J. Guttmann

Let $A$ be an $n$ by $N$ real valued random matrix, and $\h$ denote the $N$-dimensional hypercube. For numerous random matrix ensembles, the expected number of $k$-dimensional faces of the random $n$-dimensional zonotope $A\h$ obeys the…

Metric Geometry · Mathematics 2008-07-24 David L. Donoho , Jared Tanner

We study the following separation problem: Given a collection of colored objects in the plane, compute a shortest "fence" $F$, i.e., a union of curves of minimum total length, that separates every two objects of different colors. Two…

Computational Geometry · Computer Science 2021-05-11 Mikkel Abrahamsen , Panos Giannopoulos , Maarten Löffler , Günter Rote

In this paper we study critial isometric and minimal isometric embeddings of classes of Riemannian metrics which we call {\it quasi-$k$-curved metrics}. Quasi-$k$-curved metrics generalize the metrics of space forms. We construct explicit…

dg-ga · Mathematics 2008-02-03 Thomas Ivey , J. M. Landsberg

We present two algorithms for large-scale low-rank Euclidean distance matrix completion problems, based on semidefinite optimization. Our first method works by relating cliques in the graph of the known distances to faces of the positive…

Optimization and Control · Mathematics 2015-08-27 Dmitriy Drusvyatskiy , Nathan Krislock , Yuen-Lam Voronin , Henry Wolkowicz

We introduce higher order mean curvatures of screen almost conformal (SAC) half-lightlike submanifolds of indefinite contact manifolds, admitting a semi-symmetric non-metric connection, and use them to generalize some known results of [6].…

Differential Geometry · Mathematics 2016-10-25 Fortuné Massamba , Samuel Ssekajja

A quasi-metric is a distance function which satisfies the triangle inequality but is not symmetric: it can be thought of as an asymmetric metric. The central result of this thesis, developed in Chapter 3, is that a natural correspondence…

Information Retrieval · Computer Science 2008-10-31 Aleksandar Stojmirovic

In this short lecture, we compute asymptotics of orthogonal polynomials, from a saddle point approximation. This is an example of a calculation which shows the link between integrability, algebraic geometry and random matrices.

Mathematical Physics · Physics 2007-05-23 Bertrand Eynard

Gessel and Sagan investigated the Tutte polynomial, $T(x,y)$ using depth first search, and applied their techniques to show that the number of acyclic partial orientations of a graph is $2^gT(3,1/2)$. We provide a short deletion-contraction…

Combinatorics · Mathematics 2015-03-20 Spencer Backman

We compute the covering dimension the asymptotic cone of a connected Lie group. For simply connected solvable Lie groups, this is the codimension of the exponential radical. As an application of the proof, we give a characterization of…

Group Theory · Mathematics 2010-08-04 Yves de Cornulier