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Related papers: Induced and non-induced poset saturation problems

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Recall that in a laminar family, any two sets are either disjoint or contained one in the other. Here, a parametrized weakening of this condition is introduced. Let us say that a set system $\mathcal{F} \subseteq 2^X$ is $t$-laminar if $A,B…

Combinatorics · Mathematics 2014-06-13 Peter Dukes

A graph $G$ is $H$-saturated for a graph $H$, if $G$ does not contain a copy of $H$ but adding any new edge to $G$ results in such a copy. An $H$-saturated graph on a given number of vertices always exists and the properties of such graphs,…

Combinatorics · Mathematics 2020-08-21 Maria Axenovich , Mónika Csikós

For given posets $P$ and $Q$ and an integer $n$, the generalized Tur\'an problem for posets, asks for the maximum number of copies of $Q$ in a $P$-free subset of the $n$-dimensional Boolean lattice, $2^{[n]}$. In this paper, among other…

Combinatorics · Mathematics 2021-11-16 József Balogh , Ryan R. Martin , Dániel T. Nagy , Balázs Patkós

We continue the Coxeter spectral analysis of finite connected posets $I$ that are non-negative in the sense that their symmetric Gram matrix $G_I:=\frac{1}{2}(C_I + C_I^{tr})\in\mathbb{M}_{m}(\mathbb{Q})$ is positive semi-definite of rank…

Discrete Mathematics · Computer Science 2023-03-24 M. Gąsiorek

Let $\mathcal P(n)$ denote the power set of $[n]$, ordered by inclusion, and let $\mathcal P (n,p)$ denote the random poset obtained from $\mathcal P(n)$ by retaining each element from $\mathcal P (n)$ independently at random with…

Combinatorics · Mathematics 2020-06-19 Victor Falgas-Ravry , Klas Markström , Andrew Treglown , Yi Zhao

For a finite non-empty set $X$, let $\mathfrak{P}(X)$ denote the set of all posets with carrier $X$, ordered by inclusion of their partial order relations. We investigate properties of posets $P \in \mathfrak{P}(X)$ for which no lower cover…

Combinatorics · Mathematics 2025-05-20 Frank a Campo

Given a finite poset $P$, we consider the largest size $\lanp$ of a family $\F$ of subsets of $[n]:=\{1,...,n\}$ that contains no subposet $P$. This continues the study of the asymptotic growth of $\lanp$; it has been conjectured that for…

Combinatorics · Mathematics 2015-03-23 Jerrold R. Griggs , Wei-Tian Li

A graph $G$ has $p$-intersection number at most $d$ if it is possible to assign to every vertex $u$ of $G$, a subset $S(u)$ of some ground set $U$ with $|U|=d$ in such a way that distinct vertices $u$ and $v$ of $G$ are adjacent in $G$ if…

Combinatorics · Mathematics 2015-07-16 Claudson F. Bornstein , Jose W. C. Pinto , Dieter Rautenbach , Jayme L. Szwarcfiter

Given a partially order set (poset) $P$, and a pair of families of ideals $\mathcal{I}$ and filters $\mathcal{F}$ in $P$ such that each pair $(I,F)\in \mathcal{I}\times\mathcal{F}$ has a non-empty intersection, the dualization problem over…

Discrete Mathematics · Computer Science 2023-06-22 Khaled Elbassioni

In this work, we study the Induced Matching problem: Given an undirected graph $G$ and an integer $\ell$, is there an induced matching $M$ of size at least $\ell$? An edge subset $M$ is an induced matching in $G$ if $M$ is a matching such…

Data Structures and Algorithms · Computer Science 2022-12-29 Tomohiro Koana

Kahn and Kim (J. Comput. Sci., 1995) have shown that for a finite poset $P$, the entropy of the incomparability graph of $P$ (normalized by multiplying by the order of $P$) and the base-$2$ logarithm of the number of linear extensions of…

Combinatorics · Mathematics 2014-12-04 Samuel Fiorini , Selim Rexhep

This paper is about minimum cost constrained selection of inputs and outputs for generic arbitrary pole placement. The input-output set is constrained in the sense that the set of states that each input can influence and the set of states…

Optimization and Control · Mathematics 2018-01-11 Shana Moothedath , Prasanna Chaporkar , Madhu N. Belur

For a family $\mathcal{F}$ of subsets of [n]=\{1, 2, ..., n} ordered by inclusion, and a partially ordered set P, we say that $\mathcal{F}$ is P-free if it does not contain a subposet isomorphic to P. Let $ex(n, P)$ be the largest size of a…

Combinatorics · Mathematics 2016-05-24 Maria Axenovich , Jacob Manske , Ryan R. Martin

A graph $G$ is called $H$-induced-saturated if $G$ does not contain an induced copy of $H$, but removing any edge from $G$ creates an induced copy of $H$ and adding any edge of $G^{c}$ to $G$ creates an induced copy of $H$. Martin and Smith…

Combinatorics · Mathematics 2019-01-29 Eero Raty

Let $P_{n}$ be a path graph on $n$ vertices. We say that a graph $G$ is $P_{n}$-induced-saturated if $G$ contains no induced copy of $P_{n}$, but deleting any edge of $G$ as well as adding to $G$ any edge of $G^{c}$ creates such a copy.…

Combinatorics · Mathematics 2021-03-02 Vojtěch Dvořák

For a graph $H$, a graph $G$ is $H$-induced-saturated if $G$ does not contain an induced copy of $H$, but either removing an edge from $G$ or adding a non-edge to $G$ creates an induced copy of $H$. Depending on the graph $H$, an…

Combinatorics · Mathematics 2019-07-15 Eun-Kyung Cho , Ilkyoo Choi , Boram Park

A 0-1 matrix $M$ contains a 0-1 matrix $P$ if $M$ has a submatrix $P'$ which can be turned into $P$ by changing some of the ones to zeroes. Matrix $M$ is $P$-saturated if $M$ does not contain $P$, but any matrix $M'$ derived from $M$ by…

Combinatorics · Mathematics 2025-03-06 Andrew Brahms , Alan Duan , Jesse Geneson , Jacob Greene

We propose a matrix approach for generating naturally labeled posets by representing each poset $P$ on the set $[n]$ as a Boolean poset matrix $A$. This algebraic representation enables a systematic handling of partial orderings through…

Combinatorics · Mathematics 2026-05-19 Gi-Sang Cheon , Samuele Giraudo , Gukwon Kwon , Hojoon Lee

Consider, for any integer $n\ge3$, the set $\text{Pos}_n$ of all $n$-periodic tree patterns with positive topological entropy and the set $\text{Irr}_n\subset\text{Pos}_n$ of all $n$-periodic irreducible tree patterns. The aim of this paper…

Dynamical Systems · Mathematics 2025-09-10 David Juher , Francesc Mañosas , David Rojas

We introduce a notion of pattern occurrence that generalizes both classical permutation patterns as well as poset containment. Many questions about pattern statistics and avoidance generalize naturally to this setting, and we focus on…

Combinatorics · Mathematics 2014-09-16 Joshua Cooper , Anna Kirkpatrick
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