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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…

组合数学 · 数学 2015-07-07 Csaba Biró , Mitchel T. Keller , Stephen J. Young

It has been known for 30 years that posets with bounded height and with cover graphs of bounded maximum degree have bounded dimension. Recently, Streib and Trotter proved that dimension is bounded for posets with bounded height and planar…

组合数学 · 数学 2018-12-11 Bartosz Walczak

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)…

组合数学 · 数学 2022-10-13 Jakub Kozik , Piotr Micek , 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…

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…

组合数学 · 数学 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…

组合数学 · 数学 2023-04-18 Jędrzej Hodor , William T. Trotter

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…

组合数学 · 数学 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…

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

We prove that every planar poset $P$ of height $h$ has dimension at most $192h + 96$. This improves on previous exponential bounds and is best possible up to a constant factor. We complement this result with a construction of planar posets…

组合数学 · 数学 2018-01-11 Gwenaël Joret , Piotr Micek , Veit Wiechert

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…

组合数学 · 数学 2022-12-20 Heather Smith Blake , Piotr Micek , William T. Trotter

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…

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 $P$…

组合数学 · 数学 2018-12-11 William T. Trotter , Bartosz Walczak , Ruidong Wang

The queue number of a poset is the queue number of its cover graph when the vertex order is a linear extension of the poset. Heath and Pemmaraju conjectured that every poset of width $w$ has queue number at most $w$. The conjecture has been…

组合数学 · 数学 2022-08-29 Sergey Pupyrev

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…

组合数学 · 数学 2019-12-12 Stefan Felsner , Tamás Mészáros , Piotr Micek

Planar posets can have arbitrarily large dimension. However, a planar poset of height $h$ has dimension at most $192h+96$, while a planar poset with $t$ minimal elements has dimension at most $2t+1$. In particular, a planar poset with a…

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…

组合数学 · 数学 2025-10-21 Gwenaël Joret , Piotr Micek , Michał Pilipczuk , Bartosz Walczak

Motivated by the study of the dimension of random posets, it was conjectured by Bollob\'as and Brightwell in 1997 that if $P$ is a finite poset whose cover graph contains at most one cycle then its order dimension is at most $3$. In this…

组合数学 · 数学 2025-05-23 Antoine Abram , Adrien Segovia

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.

组合数学 · 数学 2019-06-18 Michał T. Seweryn

Felsner, Li and Trotter showed that the dimension of the adjacency poset of an outerplanar graph is at most 5, and gave an example of an outerplanar graph whose adjacency poset has dimension 4. We improve their upper bound to 4, which is…

组合数学 · 数学 2022-03-09 Marcin Witkowski

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…

组合数学 · 数学 2019-02-11 Gwenaël Joret , Piotr Micek , Veit Wiechert
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