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We show that posets of bounded height whose cover graphs exclude a fixed graph as a topological minor have bounded dimension. This result was already proven by Walczak. However, our argument is entirely combinatorial and does not rely on…

Combinatorics · Mathematics 2016-10-25 Piotr Micek , Veit Wiechert

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…

Combinatorics · Mathematics 2016-05-05 Gwenaël Joret , Piotr Micek , William T. Trotter , Ruidong Wang , Veit Wiechert

Over the last 30 years, researchers have investigated connections between dimension for posets and planarity for graphs. Here we extend this line of research to the structural graph theory parameter tree-width by proving that the dimension…

Combinatorics · Mathematics 2016-12-14 Gwenaël Joret , Piotr Micek , Kevin G. Milans , William T. Trotter , Bartosz Walczak , Ruidong Wang

We prove that posets of bounded height whose cover graphs belong to a fixed class with bounded expansion have bounded dimension. Bounded expansion, introduced by Ne\v{s}et\v{r}il and Ossona de Mendez as a model for sparsity in graphs, is a…

Combinatorics · Mathematics 2019-02-11 Gwenaël Joret , Piotr Micek , Veit Wiechert

It has been known for more than 40 years that there are posets with planar cover graphs and arbitrarily large dimension. Recently, Streib and Trotter proved that such posets must have large height. In fact, all known constructions of such…

Combinatorics · Mathematics 2018-12-21 David M. Howard , Noah Streib , William T. Trotter , Bartosz Walczak , Ruidong Wang

In 2015, Felsner, Trotter, and Wiechert showed that posets with outerplanar cover graphs have bounded dimension. We generalise this result to posets with $k$-outerplanar cover graphs. Namely, we show that posets with $k$-outerplanar cover…

Combinatorics · Mathematics 2021-05-04 Maximilian Gorsky , Michał T. Seweryn

Over the past 10 years, there has been considerable interest in exploring questions connecting dimension for posets with graph theoretic properties of their cover graphs and order diagrams, especially with the concepts of planarity and…

Combinatorics · Mathematics 2023-04-18 Jędrzej Hodor , William T. Trotter

Joret et al. proved that posets with cover graphs of treewidth at most 2 have dimension at most 1276. Their proof is long and very complex. We give a short and much simpler proof that the dimension of such posets is at most 12.

Combinatorics · Mathematics 2019-06-18 Michał T. Seweryn

We show that height $h$ posets that have planar cover graphs have dimension $\mathcal{O}(h^6)$. Previously, the best upper bound was $2^{\mathcal{O}(h^3)}$. Planarity plays a key role in our arguments, since there are posets such that (1)…

Combinatorics · Mathematics 2022-10-13 Jakub Kozik , Piotr Micek , William T. Trotter

The dimension is a key measure of complexity of partially ordered sets. Small dimension allows succinct encoding. Indeed if $P$ has dimension $d$, then to know whether $x \leq y$ in $P$ it is enough to check whether $x\leq y$ in each of the…

Combinatorics · Mathematics 2019-12-12 Stefan Felsner , Tamás Mészáros , Piotr Micek

Joret, Micek, Milans, Trotter, Walczak, and Wang recently asked if there exists a constant $d$ such that if $P$ is a poset with cover graph of $P$ of pathwidth at most $2$, then $\dim(P)\leq d$. We answer this question in the affirmative by…

Combinatorics · Mathematics 2015-07-07 Csaba Biró , Mitchel T. Keller , Stephen J. Young

We prove that every poset with bounded cliquewidth and with sufficiently large dimension contains the standard example of dimension $k$ as a subposet. This applies in particular to posets whose cover graphs have bounded treewidth, as the…

Combinatorics · Mathematics 2025-10-21 Gwenaël Joret , Piotr Micek , Michał Pilipczuk , Bartosz Walczak

In 1989, Ne\v{s}et\v{r}il and Pudl\'ak posed the following challenging question: Do planar posets have bounded Boolean dimension? We show that every poset with a planar cover graph and a unique minimal element has Boolean dimension at most…

Combinatorics · Mathematics 2022-12-20 Heather Smith Blake , Piotr Micek , William T. Trotter

The original notion of dimension for posets is due to Dushnik and Miller and has been studied extensively in the literature. Quite recently, there has been considerable interest in two variations of dimension known as Boolean dimension and…

Combinatorics · Mathematics 2019-06-25 Fidel Barrera-Cruz , Thomas Prag , Heather Smith , Libby Taylor , William T. Trotter

The dimension of a partially ordered set $P$ (poset for short) is the least positive integer $d$ such that $P$ is isomorphic to a subposet of $\mathbb{R}^d$ with the natural product order. Dimension is arguably the most widely studied…

Combinatorics · Mathematics 2025-12-19 Heather Smith Blake , Jędrzej Hodor , Piotr Micek , Michał T. Seweryn , William T. Trotter

In 1981, Kelly showed that planar posets can have arbitrarily large dimension. However, the posets in Kelly's example have bounded Boolean dimension and bounded local dimension, leading naturally to the questions as to whether either…

Combinatorics · Mathematics 2020-10-28 Bartłomiej Bosek , Jarosław Grytczuk , William T. Trotter

We provide proofs certifying that the structure theorem for vertex sets of bounded bidimensionality holds with polynomial bounds. The bidimensionality of vertex sets is a common generalisation of both treewidth and the face-cover-number of…

Combinatorics · Mathematics 2026-02-10 Maximilian Gorsky , Evangelos Protopapas , Sebastian Wiederrecht

Motivated by quite recent research involving the relationship between the dimension of a poset and graph-theoretic properties of its cover graph, we show that for every $d\geq 1$, if $P$ is a poset and the dimension of a subposet $B$ of $P$…

Combinatorics · Mathematics 2018-12-11 William T. Trotter , Bartosz Walczak , Ruidong Wang

We prove that a minor-closed class of graphs has bounded layered pathwidth if and only if some apex-forest is not in the class. This generalises a theorem of Robertson and Seymour, which says that a minor-closed class of graphs has bounded…

Combinatorics · Mathematics 2020-08-03 Vida Dujmović , David Eppstein , Gwenaël Joret , Pat Morin , David R. Wood

We prove two theorems concerning incidence posets of graphs, cover graphs of posets and a related graph parameter. First, answering a question of Haxell, we show that the chromatic number of a graph is not bounded in terms of the dimension…

Combinatorics · Mathematics 2013-08-13 William T. Trotter , Ruidong Wang
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