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Related papers: Classifying unavoidable Tverberg partitions

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The topological Tverberg theorem states that any continuous map of a $(d+1)(r-1)$-simplex into the Euclidean $d$-space maps some points from $r$ pairwise disjoint faces of the simplex to the same point whenever $r$ is a prime power. We…

Algebraic Topology · Mathematics 2022-02-21 Sho Hasui , Daisuke Kishimoto , Masahiro Takeda , Mitsunobu Tsutaya

Let $k, t$ be coprime integers, and let $1 \leq r \leq t$. We let $D_k^\times(r,t;n)$ denote the total number of parts among all $k$-indivisible partitions (i.e., those partitions where no part is divisible by $k$) of $n$ which are…

Combinatorics · Mathematics 2023-05-11 Faye Jackson , Misheel Otgonbayar

We prove (Theorem 2.4) that the symmetrized deleted join $SymmDelJoin(\mathcal{K})$ of a "balanced family" $\mathcal{K} = \langle K_i\rangle_{i=1}^r$ of collectively $r$-unavoidable subcomplexes of $2^{[m]}$ is $(m-r-1)$-connected. As a…

Combinatorics · Mathematics 2018-12-04 Duško Jojić , Gaiane Panina , Rade Živaljević

This paper presents a new variation of Tverberg's theorem. Given a discrete set $S$ of $R^d$, we study the number of points of $S$ needed to guarantee the existence of an $m$-partition of the points such that the intersection of the $m$…

Metric Geometry · Mathematics 2016-03-21 J. A. De Loera , R. N. La Haye , D. Rolnick , P. Soberón

We study topologization of the semigroup $\mathscr{O\!\!I}\!_n(L)$ of finite partial order isomorphisms of a bounded rank of an infinite linear ordered set $(L,\leqslant)$. In particular we show that every $T_1$ left-topological…

Group Theory · Mathematics 2025-12-01 Oleg Gutik , Maksym Shchypel

We introduce a new type of partitions that consists of partitions whose different parts alternate in parity (e.g., $3+2+2+1+1$). Various properties of this partition function are studied. In particular, we obtain its asymptotic behavior by…

Combinatorics · Mathematics 2018-03-06 Shane Chern

In recent work, M. Schneider and the first author studied a curious class of integer partitions called "sequentially congruent" partitions: the $m$th part is congruent to the $(m+1)$th part modulo $m$, with the smallest part congruent to…

Number Theory · Mathematics 2024-05-31 Robert Schneider , James A. Sellers , Ian Wagner

Recently, Andrews introduced separable integer partition classes and studied some well-known theorems. In this article, we will consider the types of partitions with restrictions on consecutive parts. We will show that such partitions are…

Combinatorics · Mathematics 2025-10-03 Y. Q. Chen , Thomas Y. He , X. M. Huang , T. T. Zou

A \emph{set partition} of the set $[n]=\{1,...c,n\}$ is a collection of disjoint blocks $B_1,B_2,...c, B_d$ whose union is $[n]$. We choose the ordering of the blocks so that they satisfy $\min B_1<\min B_2<...b<\min B_d$. We represent such…

Combinatorics · Mathematics 2007-05-23 Vit Jelinek , Toufik Mansour

Birch and Tverberg partitions are closely related concepts from discrete geometry. We show two properties for the number of Birch partitions: Evenness, and a lower bound. This implies the first non-trivial lower bound for the number of…

Combinatorics · Mathematics 2008-04-17 Stephan Hell

In this paper, we show that both 12312-avoiding partitions and 12321-avoiding partitions of the set $[n+1]$ are in one-to-one correspondence with Schr\"oder paths of semilength $n$ without peaks at even level. As a consequence, the refined…

Combinatorics · Mathematics 2009-03-09 Sherry H. F. Yan

We prove a generalization of the topological Tverberg theorem. One special instance of our general theorem is the following: Let $\Delta$ denote the 8-dimensional simplex viewed as an abstract simplicial complex, and suppose that its…

Combinatorics · Mathematics 2025-01-14 Andreas F. Holmsen , Grace McCourt , Daniel McGinnis , Shira Zerbib

We derive a formula for the expected number of blocks of a given size from a non-crossing partition chosen uniformly at random. Moreover, we refine this result subject to the restriction of having a number of blocks given. Furthermore, we…

Combinatorics · Mathematics 2012-03-16 Octavio Arizmendi

An overpartition is a partition such that the first occurrence (equivalently, the last occurrence) of a number may be overlined. In this article, we investigate three contents of overpartitions. We first consider the $r$-chain minimal and…

Combinatorics · Mathematics 2026-01-29 Y. H. Chen , Y. Q. Chen , Thomas Y. He , H. X. Huang , X. Zhang

Our basic objects are partitions of finite sets of points into disjoint subsets. We investigate sets of partitions which are closed under taking tensor products, composition and involution, and which contain certain base partitions. These…

Combinatorics · Mathematics 2015-09-04 Pierre Tarrago , Moritz Weber

Let $\mathscr{S}$ denote the set of integer partitions into parts that differ by at least $3$, with the added constraint that no two consecutive multiples of $3$ occur as parts. We derive trivariate generating functions of Andrews--Gordon…

Combinatorics · Mathematics 2021-10-27 George E. Andrews , Shane Chern , Zhitai Li

In this paper we show a variant of colorful Tverberg's theorem which is valid in any matroid: Let $S$ be a sequence of non-loops in a matroid $M$ of finite rank $m$ with closure operator cl. Suppose that $S$ is colored in such a way that…

Combinatorics · Mathematics 2019-09-20 Pavel Paták

In this paper, we address several intersection problems for $r$-cross $t$-intersecting families of partitions. A $k$-partition of an $n$-set $X$ is a set of $k$ pairwise disjoint non-empty subsets whose union is $X$. For $1\leq i\leq r$,…

Combinatorics · Mathematics 2026-02-24 Jie Wen , Benjian Lv

Let $X$ be a paracompact space, let $G$ be a finite group acting freely on $X$ and let $H$ a cyclic subgroup of $G$ of prime order $p$. Let $f:X\rightarrow M$ be a continuous map where $M$ is a connected $m$-manifold (orientable if $p>2$)…

Algebraic Topology · Mathematics 2016-11-01 Denise de Mattos , Edivaldo L. dos Santos , Taciana O. Souza

The notion of noncrossing linked partition arose from the study of certain transforms in free probability theory. It is known that the number of noncrossing linked partitions of [n+1] is equal to the n-th large Schroder number $r_n$, which…

Combinatorics · Mathematics 2007-05-23 William Y. C. Chen , Susan Y. J. Wu , Catherine Yan