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Related papers: The Crossing Tverberg Theorem

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Many of the strengthenings and extensions of the topological Tverberg theorem can be derived with surprising ease directly from the original theorem: For this we introduce a proof technique that combines a concept of "Tverberg unavoidable…

Combinatorics · Mathematics 2017-12-12 Pavle V. M. Blagojević , Florian Frick , Günter M. Ziegler

A partition on $[n]$ has a crossing if there exists $i\_1<i\_2<j\_1<j\_2$ such that $i\_1$ and $j\_1$ are in the same block, $i\_2$ and $j\_2$ are in the same block, but $i\_1$ and $i\_2$ are not in the same block. Recently, Chen et al.…

Combinatorics · Mathematics 2009-01-23 Mireille Bousquet-Mélou , Guoce Xin

In this paper a generalized topological central point theorem is proved for maps of a simplex to finite-dimensional metric spaces. Similar generalizations of the Tverberg theorem are considered.

Algebraic Topology · Mathematics 2012-02-07 R. N. Karasev

Let $\pi$ and $\lambda$ be two set partitions with the same number of blocks. Assume $\pi$ is a partition of $[n]$. For any integer $l, m \geq 0$, let $\mathcal{T}(\pi, l)$ be the set of partitions of $[n+l]$ whose restrictions to the last…

Combinatorics · Mathematics 2007-10-10 Svetlana Poznanovik , Catherine Yan

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

Combinatorics · Mathematics 2023-08-10 Vladimir Blinovsky

A tripartite-circle drawing of a tripartite graph is a drawing in the plane, where each part of a vertex partition is placed on one of three disjoint circles, and the edges do not cross the circles. We present upper and lower bounds on the…

We prove a far-reaching strengthening of Szemer\'edi's regularity lemma for intersection graphs of pseudo-segments. It shows that the vertex set of such a graph can be partitioned into a bounded number of parts of roughly the same size such…

Combinatorics · Mathematics 2023-12-05 Jacob Fox , Janos Pach , Andrew Suk

We show that any $d$-colored set of points in general position in $\mathbb{R}^d$ can be partitioned into $n$ subsets with disjoint convex hulls such that the set of points and all color classes are partitioned as evenly as possible. This…

Combinatorics · Mathematics 2019-04-04 Pavle V. M. Blagojević , Günter Rote , Johanna K. Steinmeyer , Günter M. Ziegler

A theorem of Gr\"unbaum, which states that every $m$-polytope is a refinement of an $m$-simplex, implies the following generalization of Tverberg's theorem: if $f$ is a linear function from an $m$-dimensional polytope $P$ to $\mathbb{R}^d$…

Combinatorics · Mathematics 2024-10-04 Pablo Soberón , Shira Zerbib

We prove that for any partition of the plane into a closed set $C$ and an open set $O$ and for any configuration $T$ of three points, there is a translated and rotated copy of $T$ contained in $C$ or in $O$. Apart from that, we consider…

Combinatorics · Mathematics 2011-04-29 Vit Jelinek , Jan Kyncl , Rudolf Stolar , Tomas Valla

Hadwiger's theorem is a Helly-type theorem involving common transversals to families of convex sets instead of common intersections. Subsequently, Pollack and Wenger identified a necessary and sufficient condition, called a consistent…

Combinatorics · Mathematics 2025-12-03 Ilani Axelrod-Freed , João Pedro Carvalho , Yuki Takahashi

We prove a no-dimensional version of Carath\'edory's theorem: given an $n$-element set $P\subset \Re^d$, a point $a \in \conv P$, and an integer $r\le d$, $r \le n$, there is a subset $Q\subset P$ of $r$ elements such that the distance…

Metric Geometry · Mathematics 2019-08-29 Karim Adiprasito , Imre Bárány , Nabil H. Mustafa , Tamás Terpai

We give a short proof that a uniform noncrossing partition of the regular $n$-gon weakly converges toward Aldous's Brownian triangulation of the disk, in the sense of the Hausdorff topology. This result was first obtained by Curien &…

Probability · Mathematics 2018-03-08 Jérémie Bettinelli

The existence of a nontrivial polynomially convex hull with every point a one-point Gleason part and with no nonzero bounded point derivations is established. This strengthens the \hbox{celebrated} result of Stolzenberg that there exists a…

Complex Variables · Mathematics 2016-05-16 Brian J. Cole , Swarup N. Ghosh , Alexander J. Izzo

By the theorem of Mantel $[5]$ it is known that a graph with $n$ vertices and $\lfloor \frac{n^{2}}{4} \rfloor+1$ edges must contain a triangle. A theorem of Erd\H{o}s gives a strengthening: there are not only one, but at least…

Combinatorics · Mathematics 2020-03-11 Chuanqi Xiao , Gyula O. H. Katona

We prove some injectivity, torsion-free, and vanishing theorems for simple normal crossing pairs. Our results heavily depend on the theory of mixed Hodge structures on compact support cohomology groups. We also treat several basic…

Algebraic Geometry · Mathematics 2013-01-25 Osamu Fujino

B\'ar\'any's "topological Tverberg conjecture" from 1976 states that any continuous map of an $N$-simplex $\Delta_N$ to $\mathbb{R}^d$, for $N\ge(d+1)(r-1)$, maps points from $r$ disjoint faces in $\Delta_N$ to the same point in…

Combinatorics · Mathematics 2017-05-23 Pavle V. M. Blagojević , Günter M. Ziegler

Motivated by topological Tverberg-type problems and by classical results about embeddings (maps without double points), we study the question whether a finite simplicial complex K can be mapped into R^d without triple, quadruple, or, more…

Geometric Topology · Mathematics 2015-08-13 Isaac Mabillard , Uli Wagner

Let $X$ be a partially ordered set with the property that each family of order intervals of the form $[a,b],[a,\rightarrow )$ with the finite intersection property has a nonempty intersection. We show that every directed subset of $X$ has a…

General Topology · Mathematics 2018-09-25 Rafael Espínola , Andrzej Wiśnicki

This survey presents an overview of the advances around Tverberg's theorem, focusing on the last two decades. We discuss the topological, linear-algebraic, and combinatorial aspects of Tverberg's theorem and its applications. The survey…

Combinatorics · Mathematics 2018-06-01 Imre Bárány , Pablo Soberón