English
Related papers

Related papers: Convex Hulls of Algebraic Sets

200 papers

We prove via convex integration a result that allows to pass from a so-called subsolution of the isentropic Euler equations (in space dimension at least $2$) to exact weak solutions. The method is closely related to the incompressible…

Analysis of PDEs · Mathematics 2021-07-23 Tomasz Dębiec , Jack W. D. Skipper , Emil Wiedemann

It is well known that the convex hull of $\{(x,y,xy)\}$, where $(x,y)$ is constrained to lie in a box, is given by the Reformulation-Linearization Technique (RLT) constraints. Belotti {\em et al.\,}(2010) and Miller {\em et al.\,}(2011)…

Optimization and Control · Mathematics 2020-04-16 Kurt M. Anstreicher , Samuel Burer , Kyungchan Park

For a planar point set $P$, its convex hull is the smallest convex polygon that encloses all points in $P$. The construction of the convex hull from an array $I_P$ containing $P$ is a fundamental problem in computational geometry. By…

Computational Geometry · Computer Science 2025-06-30 Ivor van der Hoog , Eva Rotenberg , Daniel Rutschmann

Counting Euclidean triangulations with vertices in a finite set $\C$ of the convex hull $\conv(\C)$ of $\C$ is difficult in general, both algorithmically and theoretically. The aim of this paper is to describe nearly convex polygons, a…

Combinatorics · Mathematics 2010-12-13 Roland Bacher , Frédéric Mouton

In this paper we study the problem of maximizing the distance to a given point over an intersection of balls. It was already known that this problem can be solved in polynomial time and space if the given point is not in the convex hull of…

Optimization and Control · Mathematics 2023-10-09 Marius Costandin , Beniamin Costandin

Let $P$ be a set of $n$ points in the plane. We compute the value of $\theta\in [0,2\pi)$ for which the rectilinear convex hull of $P$, denoted by $\mathcal{RH}_\theta(P)$, has minimum (or maximum) area in optimal $O(n\log n)$ time and…

Computational Geometry · Computer Science 2025-01-20 Carlos Alegría-Galicia , David Orden , Carlos Seara , Jorge Urrutia

This paper presents a selected tour through the theory and applications of lifts of convex sets. A lift of a convex set is a higher-dimensional convex set that projects onto the original set. Many convex sets have lifts that are…

Optimization and Control · Mathematics 2023-03-24 Hamza Fawzi , João Gouveia , Pablo A. Parrilo , James Saunderson , Rekha R. Thomas

Any solid object can be decomposed into a collection of convex polytopes (in short, convexes). When a small number of convexes are used, such a decomposition can be thought of as a piece-wise approximation of the geometry. This…

Computer Vision and Pattern Recognition · Computer Science 2020-04-14 Boyang Deng , Kyle Genova , Soroosh Yazdani , Sofien Bouaziz , Geoffrey Hinton , Andrea Tagliasacchi

We prove bounds for the number of solutions to $$a_1 + \dots + a_k = a_1' + \dots + a_k'$$ over $N$-element sets of reals, which are sufficiently convex or near-convex. A near-convex set will be the image of a set with small additive…

Number Theory · Mathematics 2021-04-26 Peter J. Bradshaw , Brandon Hanson , Misha Rudnev

We study the algebraic boundary of a convex semi-algebraic set via duality in convex and algebraic geometry. We generalize the correspondence of facets of a polytope to the vertices of the dual polytope to general semi-algebraic convex…

Algebraic Geometry · Mathematics 2014-11-04 Rainer Sinn

This paper investigates the transformation of a convex hull, derived from a d-dimensional point cloud, into a concave surface. Our primary focus is on the development of a methodology that ensures all points in the point cloud are…

Optimization and Control · Mathematics 2024-03-07 Netzer Moriya

We discuss the method of bounding suprema of canonical processes based on the inclusion of their index set into a convex hull of a well-controlled set of points. While the upper bound is immediate, the reverse estimate was established to…

Probability · Mathematics 2024-05-24 Rafał Latała

This paper presents a new algorithm for the convex hull problem, which is based on a reduction to a combinatorial decision problem POLYTOPE-COMPLETENESS-COMBINATORIAL, which in turn can be solved by a simplicial homology computation. Like…

Metric Geometry · Mathematics 2007-05-23 Michael Joswig , G"unter M. Ziegler

In this work, we present a new efficient method for convex shape representation, which is regardless of the dimension of the concerned objects, using level-set approaches. Convexity prior is very useful for object completion in computer…

Computer Vision and Pattern Recognition · Computer Science 2020-03-24 Lingfeng li , Shousheng Luo , Xue-Cheng Tai , Jiang Yang

In this paper we study the problem of calculating the convex hull of certain affine algebraic varieties. As we explain, the motivation for considering this problem is that certain pure-state measures of quantum entanglement, which we call…

Quantum Physics · Physics 2007-05-23 Tobias J. Osborne

Given an affine variety X and a finite dimensional vector space of regular functions L on X, we associate a convex body to (X, L) such that its volume is responsible for the number of solutions of a generic system of functions from L. This…

Algebraic Geometry · Mathematics 2008-04-28 Kiumars Kaveh , Askold G. Khovanskii

In this paper we introduce and study a topological abelian group of convex bodies, analogous to the scissors congruence group and McMullen's polytope algebra, with the universal property that continuous valuations on convex bodies…

Metric Geometry · Mathematics 2022-07-29 Richard Hepworth

The article deals with operations defined on convex polyhedra or polyhedral convex functions. Given two convex polyhedra, operations like Minkowski sum, intersection and closed convex hull of the union are considered. Basic operations for…

Optimization and Control · Mathematics 2018-07-17 Daniel Ciripoi , Andreas Löhne , Benjamin Weißing

The random polytope $K_n$, defined as the convex hull of $n$ points chosen uniformly at random on the boundary of a smooth convex body, is considered. Proofs for lower and upper variance bounds, strong laws of large numbers and central…

Probability · Mathematics 2017-06-12 Nicola Turchi , Florian Wespi

It is shown that a simple closed curve in $\mathbb C^n$ that is a uniform limit of rectifiable simple closed curves each of which has nontrivial polynomial hull has itself nontrivial polynomial hull. In case the limit curve is rectifiable,…

Complex Variables · Mathematics 2021-05-21 Alexander J. Izzo , Edgar Lee Stout