English
Related papers

Related papers: On a degeneracy ratio for bounded convex polytopes

200 papers

We give examples of measures on certain k-surfaces in R^d. These measures satisfy convolution estimates which are nearly optimal.

Classical Analysis and ODEs · Mathematics 2007-06-25 Daniel Oberlin

The geometry of the Birkhoff polytope, i.e., the compact convex set of all $n \times n$ doubly stochastic matrices, has been an active subject of research. While its faces, edges and facets as well as its volume have been intensely studied,…

Metric Geometry · Mathematics 2023-10-24 Ludovick Bouthat , Javad Mashreghi , Frédéric Morneau-Guérin

Letting $P$ be a convex polytope in $\mathbb{R}^d$ with $n>d$ vertices, we study geometric and analytical properties of the set of generalized barycentric coordinates relative to any point $p\in P$. We prove that such sets are polytopes in…

Metric Geometry · Mathematics 2024-03-01 Fabio V. Difonzo

There are (at least) two reasons to study random polytopes. The first is to understand the combinatorics and geometry of random polytopes especially as compared to other classes of polytopes, and the second is to analyze average-case…

Probability · Mathematics 2019-05-02 Andrew Newman

The radius of regularity sometimes spelled as the radius of nonsingularity is a measure providing the distance of a given matrix to the nearest singular one. Despite its possible application strength this measure is still far from being…

Numerical Analysis · Mathematics 2019-05-28 David Hartman , Milan Hladik

It is shown that the geometric measure of entanglement of a pure multipartite state satisfies a polynomial equation, generalising the characteristic equation of the matrix of coefficients of a bipartite state. The equation is solved for a…

Quantum Physics · Physics 2010-07-06 Joseph J. Hilling , Anthony Sudbery

In this survey on local additive invariants of real and complex definable singular germs we systematically present classical or more recent invariants of different nature as emerging from a tame degeneracy principle. For this goal, we…

Algebraic Geometry · Mathematics 2013-11-01 Georges Comte

The ratio of convexity radius over injectivity radius may be made arbitrarily small within the class of compact Riemannian manifolds of any fixed dimension at least two. This is proved using Gulliver's method of constructing manifolds with…

Differential Geometry · Mathematics 2017-03-22 James Dibble

We analyze surface patches with a corner that is rounded in the sense that the partial derivatives at that point are antiparallel. Sufficient conditions for $G^1$ smoothness are given, which, up to a certain degenerate case, are also…

Computational Geometry · Computer Science 2022-11-18 Benjamin Marussig , Ulrich Reif

We study the combinatorial complexity of D-dimensional polyhedra defined as the intersection of n halfspaces, with the property that the highest dimension of any bounded face is much smaller than D. We show that, if d is the maximum…

Computational Geometry · Computer Science 2013-07-30 David Eppstein , Maarten Löffler

We study extremal properties of spherical random polytopes, the convex hull of random points chosen from the unit Euclidean sphere in $\mathbb{R}^n$. The extremal properties of interest are the expected values of the maximum and minimum…

Probability · Mathematics 2025-01-16 Brett Leroux , Luis Rademacher , Carsten Schütt , Elisabeth M. Werner

The mixing operation for abstract polytopes gives a natural way to construct the minimal common cover of two polytopes. In this paper, we apply this construction to the regular convex polytopes, determining when the mix is again a polytope,…

Combinatorics · Mathematics 2012-01-17 Gabe Cunningham

We investigate the regularity of the marginals onto hyperplanes for sets of finite perimeter. We prove, in particular, that if a set of finite perimeter has log-concave marginals onto a.e. hyperplane then the set is convex.

Metric Geometry · Mathematics 2015-02-24 Alessio Figalli , David Jerison

We show that the size of a minimal simplicial cover of a polytope $P$ is a lower bound for the size of a minimal triangulation of $P$, including ones with extra vertices. We then use this fact to study minimal triangulations of cubes, and…

Combinatorics · Mathematics 2007-05-23 Adam Bliss , Francis Edward Su

We construct the geometric quantization of a compact surface using a singular real polarization coming from an integrable system. Such a polarization always has singularities, which we assume to be of nondegenerate type. In particular, we…

Symplectic Geometry · Mathematics 2012-06-12 Mark D. Hamilton , Eva Miranda

In this paper we introduce a new sequence of quantities for random polytopes. Let $K_N=\conv\{X_1,...,X_N\}$ be a random polytope generated by independent random vectors uniformly distributed in an isotropic convex body $K$ of $\R^n$. We…

Functional Analysis · Mathematics 2012-11-13 David Alonso-Gutierrez , Nikos Dafnis , Maria A. Hernandez Cifre , Joscha Prochno

The Upper Bound Theorem for convex polytopes implies that the $p$-th Betti number of the \v{C}ech complex of any set of $N$ points in $\mathbb R^d$ and any radius satisfies $\beta_{p} = O(N^{m})$, with $m = \min \{ p+1, \lceil d/2 \rceil…

Combinatorics · Mathematics 2023-10-24 Herbert Edelsbrunner , János Pach

When the standard representation of a crystallographic Coxeter group G (with string diagram) is reduced modulo the integer d>1, one obtains a finite group G^d which is often the automorphism group of an abstract regular polytope. Building…

Combinatorics · Mathematics 2008-05-23 B. Monson , Egon Schulte

Near a singular point of a surface or a curve, geometric invariants diverge in general, and the orders of diverge, in particular the boundedness about these invariants represent geometry of the surface and the curve. In this paper, we study…

Differential Geometry · Mathematics 2024-10-14 Luciana F. Martins , Kentaro Saji , Samuel P. dos Santos , Keisuke Teramoto

In this paper we prove a series of Rogers-Shephard type inequalities for convex bodies when dealing with measures on the Euclidean space with either radially decreasing densities, or quasi-concave densities attaining their maximum at the…