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Related papers: Tverberg-type theorems for intersecting by rays

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In this paper we consider families of compact convex sets in $\mathbb R^d$ such that any subfamily of size at most $d$ has a nonempty intersection. We prove some analogues of the central point theorem and Tverberg's theorem for such…

Metric Geometry · Mathematics 2013-08-23 R. N. Karasev

Given a finite set of points in $\mathbb{R}^d$, Tverberg's theorem guarantees the existence of partitions of this set into parts whose convex hulls intersect. We introduce a graph structured on the family of Tverberg partitions of a given…

Combinatorics · Mathematics 2023-10-13 Deborah Oliveros , Érika Roldán , Pablo Soberón , Antonio J. Torres

We present projective versions of the center point theorem and Tverberg's theorem, interpolating between the original and the so-called "dual" center point and Tverberg theorems. Furthermore we give a common generalization of these and many…

Algebraic Topology · Mathematics 2014-09-23 Roman Karasev , Benjamin Matschke

This paper discusses Tverberg-type theorems with coordinate constraints (i.e., versions of these theorems where all points lie within a subset $S \subset \mathbb{R}^d$ and the intersection of convex hulls is required to have a non-empty…

Metric Geometry · Mathematics 2019-01-30 Jesús A. De Loera , Thomas A. Hogan , Frédéric Meunier , Nabil Mustafa

We prove the complete intersection theorem and complete nontrivial-intersection theorem for systems of set partitions

Combinatorics · Mathematics 2023-08-10 Vladimir Blinovsky

Tverberg's theorem bounds the number of points $\mathbb{R}^d$ needed for the existence of a partition into $r$ parts whose convex hulls intersect. If the points are colored with $N$ colors, we seek partitions where each part has at most one…

Combinatorics · Mathematics 2020-05-28 Sherry Sarkar , Pablo Soberón

The colorful Helly theorem and Tverberg's theorem are fundamental results in discrete geometry. We prove a theorem which interpolates between the two. In particular, we show the following for any integers $d \geq m \geq 1$ and $k$ a prime…

Combinatorics · Mathematics 2024-03-25 Michael Gene Dobbins , Andreas F. Holmsen , Dohyeon Lee

Tverberg's theorem is one of the cornerstones of discrete geometry. It states that, given a set $X$ of at least $(d+1)(r-1)+1$ points in $\mathbb R^d$, one can find a partition $X=X_1\cup \ldots \cup X_r$ of $X$, such that the convex hulls…

Computational Geometry · Computer Science 2021-04-13 Radoslav Fulek , Bernd Gärtner , Andrey Kupavskii , Pavel Valtr , Uli Wagner

A seminal theorem of Tverberg states that any set of $T(r,d)=(r-1)(d+1)+1$ points in $\mathbb{R}^d$ can be partitioned into $r$ subsets whose convex hulls have non-empty $r$-fold intersection. Almost any collection of fewer points in…

Combinatorics · Mathematics 2023-11-10 Leah Leiner , Steven Simon

Given a family of sets on the plane, we say that the family is intersecting if for any two sets from the family their interiors intersect. In this paper, we study intersecting families of triangles with vertices in a given set of points. In…

Combinatorics · Mathematics 2021-02-19 Peter Frankl , Andreas Holmsen , Andrey Kupavskii

We study versions of Helly's theorem that guarantee that the intersection of a family of convex sets in $R^d$ has a large diameter. This includes colourful, fractional and $(p,q)$ versions of Helly's theorem. In particular, the fractional…

Metric Geometry · Mathematics 2015-09-29 Pablo Soberón

We prove that every pointed closed convex set in $\mathbb{R}^n$ is the intersection of all the rational closed halfspaces that contain it. This generalizes a previous result by the authors for compact convex sets.

Optimization and Control · Mathematics 2018-02-12 Marcel K. de Carli Silva , Levent Tunçel

The topological Tverberg theorem claims that for any continuous map of the (q-1)(d+1)-simplex to R^d there are q disjoint faces such that their images have a non-empty intersection. This has been proved for affine maps, and if $q$ is a…

Combinatorics · Mathematics 2008-02-25 Stephan Hell

We obtain algorithms for computing Tverberg partitions based on centerpoint approximations. This applies to a wide range of convexity spaces, from the classic Euclidean setting to geodetic convexity in graphs. In the Euclidean setting, we…

Computational Geometry · Computer Science 2017-11-03 David Rolnick , Pablo Soberón

Tverberg's theorem asserts that every (k-1)(d+1)+1 points in R^d can be partitioned into k parts, so that the convex hulls of the parts have a common intersection. Calder and Eckhoff asked whether there is a purely combinatorial deduction…

Combinatorics · Mathematics 2010-09-14 Boris Bukh

We introduce the following generalization of set intersection via characteristic vectors: for $n,q,s, t \ge 1$ a family $\mathcal{F}\subseteq \{0,1,\dots,q\}^n$ of vectors is said to be \emph{$s$-sum $t$-intersecting} if for any distinct…

Combinatorics · Mathematics 2023-05-03 Balázs Patkós , Zsolt Tuza , Máté Vizer

Let P be a d-dimensional n-point set. A Tverberg-partition of P is a partition of P into r sets P_1, ..., P_r such that the convex hulls conv(P_1), ..., conv(P_r) have non-empty intersection. A point in the intersection of the conv(P_i)'s…

Computational Geometry · Computer Science 2020-07-02 Wolfgang Mulzer , Daniel Werner

$\newcommand{\floor}[1]{\left\lfloor {#1} \right\rfloor} \renewcommand{\Re}{\mathbb{R}}$ Tverberg's theorem states that a set of $n$ points in $\Re^d$ can be partitioned into $\floor{n/(d+1)}$ sets with a common intersection. A point in…

Computational Geometry · Computer Science 2023-05-03 Sariel Har-Peled , Timothy Zhou

Tverberg's theorem states that any set of $t(r,d)=(r-1)(d+1)+1$ points in $\mathbb{R}^d$ can be partitioned into $r$ subsets whose convex hulls have non-empty $r$-fold intersection. Moreover, generic collections of fewer points cannot be so…

Combinatorics · Mathematics 2023-11-10 Steven Simon , Tobias Timofeyev

We introduce complex intersection bodies and show that their properties and applications are similar to those of their real counterparts. In particular, we generalize Busemann's theorem to the complex case by proving that complex…

Functional Analysis · Mathematics 2014-02-26 A. Koldobsky , G. Paouris , M. Zymonopoulou
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