English
Related papers

Related papers: Dimension of Restricted Classes of Interval Orders

200 papers

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…

Combinatorics · Mathematics 2007-06-12 Geir Agnarsson

Properties of intervals in the lattice of antichains of subsets of a universe of finite size are investigated. New objects and quantities in this lattice are defined. Expressions and numerical values are deduced for the number of connected…

Combinatorics · Mathematics 2014-07-25 Patrick De Causmaecker , Stefan De Wannemacker

We introduce a continuum of dimensions which are `intermediate' between the familiar Hausdorff and box dimensions. This is done by restricting the families of allowable covers in the definition of Hausdorff dimension by insisting that $|U|…

Metric Geometry · Mathematics 2021-03-26 Kenneth J. Falconer , Jonathan M. Fraser , Tom Kempton

We show that the order dimension of the weak order on a Coxeter group of type A, B or D is equal to the rank of the Coxeter group, and give bounds on the order dimensions for the other finite types. This result arises from a unified…

Combinatorics · Mathematics 2026-05-13 Nathan Reading

Hepworth, Willerton, Leinster and Shulman introduced the magnitude homology groups for enriched categories, in particular, for metric spaces. The purpose of this paper is to describe the magnitude homology group of a metric space in terms…

Algebraic Topology · Mathematics 2021-09-03 Ryuki Kaneta , Masahiko Yoshinaga

Schnyder characterized planar graphs in terms of order dimension. Brightwell and Trotter proved that the dimension of the vertex-edge-face poset $\Pvef{M}$ of a planar map $M$ is at most four. In this paper we investigate cases where…

Combinatorics · Mathematics 2009-06-03 Stefan Felsner , Johan Nilsson

In 2010, Bousquet-M\'elou et al. defined sequences of nonnegative integers called ascent sequences and showed that the ascent sequences of length $n$ are in one-to-one correspondence with the interval orders, i.e., the posets not containing…

Combinatorics · Mathematics 2020-04-20 Mitchel T. Keller , Stephen J. Young

Metric embeddings traditionally study how to map $n$ items to a target metric space such that distance lengths are not heavily distorted; but what if we only care to preserve the relative order of the distances (and not their length)? In…

Data Structures and Algorithms · Computer Science 2024-01-01 Vaggos Chatziafratis , Piotr Indyk

The set of all permutations, ordered by pattern containment, is a poset. We present an order isomorphism from the poset of permutations with a fixed number of descents to a certain poset of words with subword order. We use this bijection to…

Combinatorics · Mathematics 2015-07-31 Jason P. Smith

Complex structures can only form in a universe that allows for bound states. While this is clearly observed in three-dimensions, added degrees of freedom in a higher-dimensional space preclude the immediate assumption that binding…

We study the maximum size of Sidon sets in unions of integers intervals. If $A\subseteq\mathbb{N}$ is the union of two intervals and if $\left| A \right|=n$ (where $\left| A \right|$ denotes the cardinality of $A$), we prove that $A$…

Combinatorics · Mathematics 2022-02-04 Robin Riblet

We introduce a notion of dimension for the solution set of a system of algebraic difference equations that measures the degrees of freedom when determining a solution in the ring of sequences. This number need not be an integer, but, as we…

Algebraic Geometry · Mathematics 2020-11-23 Michael Wibmer

Heath and Pemmaraju conjectured that the queue-number of a poset is bounded by its width and if the poset is planar then also by its height. We show that there are planar posets whose queue-number is larger than their height, refuting the…

Combinatorics · Mathematics 2018-09-10 Kolja Knauer , Piotr Micek , Torsten Ueckerdt

In order theory, a rank function measures the vertical "level" of a poset element. It is an integer-valued function on a poset which increments with the covering relation, and is only available on a graded poset. Defining a vertical measure…

Combinatorics · Mathematics 2014-09-24 Cliff Joslyn , Emilie Hogan , Alex Pogel

We characterize the downsets of integer partitions (ordered by containment of Ferrers diagrams) and compositions (ordered by the generalized subword order) which have finite dimension in the sense of Dushnik and Miller. In the case of…

Combinatorics · Mathematics 2017-03-22 Michael Engen , Vincent Vatter

With each piecewise monotonic map of the unit interval, a dimension triple is associated. The dimension triple, viewed as a Z[t, t^{-1}] module, is finitely generated, and generators are identified. Dimension groups are computed for Markov…

Dynamical Systems · Mathematics 2007-05-23 Fred Shultz

In 1986 Stanley associated to a poset the order polytope. The close interplay between its combinatorial and geometric properties makes the order polytope an object of tremendous interest. Double posets were introduced in 2011 by Malvenuto…

Combinatorics · Mathematics 2022-09-15 Aenne Benjes

In arXiv:2207.08617 [math.DG] Brendle-Hirsch-Johne proved that $T^m\times S^{n-m}$ does not admit metrics with positive $m$-intermediate curvature when $n\leq 7$. Chu-Kwong-Lee showed in arXiv:2208.12240 [math.DG] a corresponding rigidity…

Differential Geometry · Mathematics 2024-10-01 Kai Xu

A Besicovitch set is a set which contains a unit line segment in any direction. It is known that the Minkowski and Hausdorff dimensions of such a set must be greater than or equal to 5/2 in \R^3. In this paper we show that the Minkowski…

Classical Analysis and ODEs · Mathematics 2007-05-23 Nets Hawk Katz , Izabella Łaba , Terence Tao

We show that the number of unit distances determined by n points in R^3 is O(n^{3/2}), slightly improving the bound of Clarkson et al. established in 1990. The new proof uses the recently introduced polynomial partitioning technique of Guth…

Combinatorics · Mathematics 2011-07-07 Haim Kaplan , Jiri Matousek , Zuzana Safernova , Micha Sharir