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We prove that each bounded polytope can be represented as a polynomial zonotope, which we refer to as the Z-representation of polytopes. Previous representations are the vertex representation (V-representation) and the halfspace…

组合数学 · 数学 2019-10-17 Niklas Kochdumper , Matthias Althoff

We consider 'supersaturation' problems in partially ordered sets (posets) of the following form. Given a finite poset $P$ and an integer $m$ greater than the cardinality of the largest antichain in $P$, what is the minimum number of…

组合数学 · 数学 2017-08-29 Jonathan A. Noel , Alex Scott , Benny Sudakov

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…

组合数学 · 数学 2007-05-23 Adam Bliss , Francis Edward Su

We study two new parameters for finite posets motivated by the problem of efficiently determining the set of successors of a given element. A plane map of a poset $P=(X,\leq)$ is an injective mapping of $X$ into the Cartesian plane…

组合数学 · 数学 2026-05-21 Stefan Felsner , Jędrzej Hodor , Giacomo Ortali , Alexander Wolff

The purpose of this paper is to study stable representations of partially ordered sets (posets) and compare it to the well known theory for quivers. In particular, we prove that every indecomposable representation of a poset of finite type…

表示论 · 数学 2019-02-27 Vyacheslav Futorny , Kostiantyn Iusenko

Rabinovitch showed in 1978 that the interval orders having a representation consisting of only closed unit intervals have order dimension at most 3. This article shows that the same dimension bound applies to two other classes of posets:…

组合数学 · 数学 2022-01-05 Mitchel T. Keller , Ann N. Trenk , Stephen J. Young

We define a proportionally dense subgraph (PDS) as an induced subgraph of a graph with the property that each vertex in the PDS is adjacent to proportionally as many vertices in the subgraph as in the graph. We prove that the problem of…

计算复杂性 · 计算机科学 2020-06-11 Cristina Bazgan , Janka Chlebíková , Clément Dallard , Thomas Pontoizeau

In 1977, Trotter and Moore proved that a poset has dimension at most $3$ whenever its cover graph is a forest, or equivalently, has treewidth at most $1$. On the other hand, a well-known construction of Kelly shows that there are posets of…

组合数学 · 数学 2016-05-05 Gwenaël Joret , Piotr Micek , William T. Trotter , Ruidong Wang , Veit Wiechert

Effective representation of data is crucial in various machine learning tasks, as it captures the underlying structure and context of the data. Embeddings have emerged as a powerful technique for data representation, but evaluating their…

机器学习 · 计算机科学 2023-09-21 Sarwan Ali

Sidon sets are those sets such that the sums of two of its elements never coincide. They go back to the 30s when Sidon asked for the maximal size of a subset of consecutive integers with that property. This question is now answered in a…

数论 · 数学 2016-11-10 Laurent Habsieger , Alain Plagne

The purpose of this paper is twofold: 1) Applications of Gallagher's larger sieve modulo prime squares do not work. In some relevant cases we can transform the residue class information modulo $p^2$ to more suitable residue information…

数论 · 数学 2026-03-19 Rainer Dietmann , Christian Elsholtz , Imre Ruzsa

It is a widely observed phenomenon in computer graphics that the size of the silhouette of a polyhedron is much smaller than the size of the whole polyhedron. This paper provides, for the first time, theoretical evidence supporting this for…

计算几何 · 计算机科学 2009-09-29 Marc Glisse , Sylvain Lazard

Earlier an arbitrary poset $P$ was proved to be isomorphic to the collection of subsets of a space $M$ with two closures which are closed in the first closure and open in the other. As a space $M$ for this representation an algebraic dual…

一般拓扑 · 数学 2007-05-23 R. Breslav , A. Stavrova , R. R. Zapatrin

A family of simplicial complexes, connected with simplicial maps and indexed by a poset $P$, is called a poset tower. The concept of poset towers subsumes classical objects of study in the persistence literature, as, for example,…

代数拓扑 · 数学 2025-05-14 Tamal K. Dey , Florian Russold

In this paper, we address a particular variation of the Tur\'an problem for the hypercube. Alon, Krech and Szab\'o (2007) asked "In an n-dimensional hypercube, Qn, and for l < d < n, what is the size of a smallest set, S, of Q_l's so that…

组合数学 · 数学 2011-10-04 Brendon Stanton , Lale Özkahya

A poset $\mathbf{P} = (X,\preceq)$ is {\em $m$-partite} if $X$ has a partition $X = X_1 \cup ... \cup X_m$ such that (1) each $X_i$ forms an antichain in $\mathbf{P}$, and (2) $x\prec y$ implies $x\in X_i$ and $y\in X_j$ where $i<j$. In…

组合数学 · 数学 2007-06-12 Geir Agnarsson

Possible short and semi-short representations for $\N=2$ and $\N=4$ superconformal symmetry in four dimensions are discussed. For $\N=4$ the well known short supermultiplets whose lowest dimension conformal primary operators correspond to…

高能物理 - 理论 · 物理学 2009-11-07 F. A. Dolan , H. Osborn

Given a smooth complex variety $X$, an algebraically skew embedding of $X$ is an embedding of $X$ into a complex projective space $\mathbb{P}^N$ such that for any two points $x,y\in X$, their embedded tangent spaces in $\mathbb{P}^N$ do not…

代数几何 · 数学 2025-05-06 Andy B. Day

We study cubic realizations of posets compatible with projection maps, meaning that the projection is represented by deletion of the last coordinate. For cylindrical projections, we introduce the pre-Reeb graph and the augmented pre-Reeb…

组合数学 · 数学 2026-04-28 Daria Poliakova

For every integer $n$ with $n \geq 4$, we prove that the local dimension of a poset consisting of all the subsets of $\{1,\dots,n\}$ equipped with the inclusion relation is strictly less than $n$, answering a question of Kim, Martin,…

组合数学 · 数学 2025-12-16 Jędrzej Hodor , Jakub Sordyl