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We show that the Union-Closed Conjecture holds for the union-closed family generated by the cyclic translates of any fixed set.

Combinatorics · Mathematics 2020-12-08 James Aaronson , David Ellis , Imre Leader

The Union Closed Sets Conjecture is one of the most renowned problems in combinatorics. Its appeal lies in the simplicity of its statement contrasted with the potential complexity of its resolution. The conjecture posits that, in any union…

Combinatorics · Mathematics 2025-10-02 Nived J M

Let G be a graph with vertices V and edges E. Let F be the union-closed family of sets generated by E. Then F is the family of subsets of V without isolated points. Theorem: There is an edge e belongs to E such that |{U belongs to F | e…

Combinatorics · Mathematics 2016-09-06 Emanuel Knill

We provide a simple proof for the union-closed sets conjecture, a long-standing open problem in set theory with immediate applications to graph theory, number theory, and order-theory.

Combinatorics · Mathematics 2016-07-08 Sven Schäge

By finding orthogonal representation for a family of simple connected called $\delta$-graphs it is possible to show that $\delta$-graphs satisfy delta conjecture. An extension of the argument to graphs of the form…

Combinatorics · Mathematics 2018-06-20 Pedro Díaz Navarro

The edges surrounding a face of a map $M$ form a cycle $C$, called the boundary cycle of the face, and $C$ is often not a simple cycle. If the map $M$ is arc-transitive, then there is a cyclic subgroup of automorphisms of $M$ which leaves…

Combinatorics · Mathematics 2021-11-05 Jiyong Chen , Cai Heng Li , Cheryl E. Praeger , Shu-Jiao Song

The Union Closed Sets Conjecture states that in every finite, nontrivial set family closed under taking unions there is an element contained in at least half of all the sets of the family. We investigate two new directions with respect to…

Combinatorics · Mathematics 2023-04-05 Nicolas Nagel

In 1979 Frankl conjectured that in a finite non-trivial union-closed collection of sets there has to be an element that belongs to at least half the sets. We show that this is equivalent to the conjecture that in a finite non-trivial graph…

Combinatorics · Mathematics 2013-05-17 Henning Bruhn , Pierre Charbit , Oliver Schaudt , Jan Arne Telle

The family of graphs of reduced words of a certain subcollection of permutations in the union $\cup_{n\geq 4}\frak{S}_{n}$ of symmetic groups is investigated. The subcollection is characterised by the hook cycle type $(n-2,1,1)$ with…

Combinatorics · Mathematics 2024-06-17 Praise Adeyemo

A classical enumerative result states that, given a graph $G$ and a vertex $u$, the number of connected subgraphs of $G$ is equal to the number of orientations of $G$ such that every vertex can reach $u$ by a directed path. We show that…

Combinatorics · Mathematics 2026-05-18 Oliver Bernardi , Jonathan J. Fang

A CIS graph is a graph in which every maximal stable set and every maximal clique intersect. A graph is well-covered if all its maximal stable sets are of the same size, co-well-covered if its complement is well-covered, and…

Combinatorics · Mathematics 2016-08-08 Edward Dobson , Ademir Hujdurović , Martin Milanič , Gabriel Verret

The family of cycle completable graphs has several cryptomorphic descriptions, the equivalence of which has heretofore been proven by a laborious implication-cycle that detours through a motivating matrix completion problem. We give a…

Combinatorics · Mathematics 2023-09-06 Maria Chudnovsky , Ian Malcolm Johnson McInnis

We provide a proof of the union-closed sets conjecture, by means of a suitable refinement of the breakthrough entropy-approach introduced by Gilmer. The novelty here is to consider a convex combination of $A$ and $A\cup B$, where $A,B$ are…

Combinatorics · Mathematics 2023-02-09 Raffaele Scandone

The Cycle double cover (CDC) conjecture states that for every bridgeless graph $G$, there exists a family $\mathcal{F}$ of cycles such that each edge of the graph is contained in exactly two members of $\mathcal{F}$. Given an embedding of a…

Combinatorics · Mathematics 2025-11-11 Babak Ghanbari , Robert Šámal

We prove Union-Closed sets conjecture.

Combinatorics · Mathematics 2024-09-13 Vladimir Blinovsky , Llohann D Speranca

A family of sets $\mathcal{A}$ is union-closed if it is finite and nonempty with member sets that are all finite and distinct (at least one of which is nonempty) and it satisfies the property $X, Y \in \mathcal{A} \implies X \cup Y \in…

Combinatorics · Mathematics 2024-09-25 Christopher Bouchard

Frankl's union-closed sets conjecture states that in every finite union-closed set of sets, there is an element that is contained in at least half of the member-sets (provided there are at least two members). The conjecture has an…

Combinatorics · Mathematics 2013-03-01 Henning Bruhn , Oliver Schaudt

The Graded Classification Conjecture (GCC) states that the pointed $K_0^{\operatorname{gr}}$-group is a complete invariant of the Leavitt path algebras of finite graphs when these algebras are considered with their natural grading by…

Rings and Algebras · Mathematics 2026-03-03 Lia Vas

The classical Whitney's 2-Isomorphism Theorem describes the families of graphs having the same cycle matroid. In this paper we describe the families of graphs having the same truncated cycle matroid and prove, in particular, that every…

Combinatorics · Mathematics 2022-10-03 Jose De Jesus , Alexander Kelmans

Universal cycles, such as De Bruijn cycles, are cyclic sequences of symbols that represent every combinatorial object from some family exactly once as a consecutive subsequence. Graph universal cycles are a graph analogue of universal…

Combinatorics · Mathematics 2023-08-14 Rachel Kirsch , Clare Sibley , Elizabeth Sprangel
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