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Related papers: The Alon-Tarsi number of Halin graphs

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The Alon-Tarsi number $AT(G)$ of a graph $G$ is the smallest $k$ for which there is an orientation $D$ of $G$ with max indegree $k-1$ such that the number of even and odd circulations contained in D are different. In this paper, we show…

Combinatorics · Mathematics 2020-01-01 Zhiguo Li , Zeling Shao , Fedor Petrov , Alexey Gordeev

The Alon-Tarsi number of a graph $ G $ is the smallest $ k $ such that there exists an orientation $ D $ of $ G $ with maximum outdegree $ k - 1 $ satisfying that the number of even Eulerian subgraphs is different from the number of odd…

Combinatorics · Mathematics 2026-03-10 Zhiguo Li , Zhentao Jiao , Zeling Shao

This paper gives a simple proof of the result that every planar graph $G$ has Alon-Tarsi number at most 5, and has a matching $M$ such that $G-M$ has Alon-Tarsi number at most 4.

Combinatorics · Mathematics 2022-03-31 Yangyan Gu , Xuding Zhu

We study the list chromatic number of Cartesian products of graphs through the Alon-Tarsi number as defined by Jensen and Toft (1995) in their seminal book on graph coloring problems. The Alon-Tarsi number of $G$, $AT(G)$, is the smallest…

Combinatorics · Mathematics 2018-03-21 Hemanshu Kaul , Jeffrey A. Mudrock

The \emph{Alon-Tarsi number} of a graph $G$ is the smallest $k$ so that there exists an orientation $D$ of $G$ with max outdegree $k-1$ satisfying the number of even Eulerian subgraphs different from the number of odd Eulerian subgraphs. In…

Combinatorics · Mathematics 2025-04-08 Zhiguo Li , Yujia Gai , Zeling Shao

In this paper, we show the following three theorems. Let $G$ be a $K_5$-minor-free graph. Then Alon-Tarsi number of $G$ is at most $5$, there exists a matching $M$ of $G$ such that the Alon-Tarsi number of $G-M$ is at most $4$, and there…

Combinatorics · Mathematics 2019-11-12 Toshiki Abe , Seog-Jin Kim , Kenta Ozeki

The Alon-Tarsi number of a polynomial is a parameter related to the exponents of its monomials. For graphs, their Alon-Tarsi number is the Alon-Tarsi number of their graph polynomials. As such, it provides an upper bound on their choice and…

Combinatorics · Mathematics 2024-04-16 S. Prajnanaswaroopa

This paper proves that the Alon-Tarsi number of any planar graph is at most $5$, which gives an alternate proof of the $5$-choosability as well as the $5$-paintability of planar graphs.

Combinatorics · Mathematics 2017-11-30 Xuding Zhu

Oriented chromatic number of an oriented graph $G$ is the minimum order of an oriented graph $H$ such that $G$ admits a homomorphism to $H$. The oriented chromatic number of an unoriented graph $G$ is the maximal chromatic number over all…

Discrete Mathematics · Computer Science 2019-09-04 Janusz Dybizbański , Andrzej Szepietowski

Let $(G,\sigma)$ be any signed planar graph. We show that the Alon-Tarsi number of $(G,\sigma)$ is at most 5, generalizing a recent result of Zhu for unsigned case. In addition, if $(G,\sigma)$ is $2$-colorable then $(G,\sigma)$ has the…

Combinatorics · Mathematics 2018-09-11 Wei Wang , Jianguo Qian

A graph $G$ of order $n$ is called edge-pancyclic if, for every integer $k$ with $3 \leq k \leq n$, every edge of $G$ lies in a cycle of length $k$. Determining the minimum size $f(n)$ of a simple edge-pancyclic graph with $n$ vertices…

Combinatorics · Mathematics 2025-11-04 Xiamiao Zhao , Yuxuan Yang

In a seminal paper, Alon and Tarsi have introduced an algebraic technique for proving upper bounds on the choice number of graphs (and thus, in particular, upper bounds on their chromatic number). The upper bound on the choice number of $G$…

Combinatorics · Mathematics 2009-11-12 Dan Hefetz

A Halin graph is a graph constructed by embedding a tree with no vertex of degree two in the plane and then adding a cycle to join the tree's leaves. The Halin Tur\'an number of a graph $F$, denoted as $\ex_{\hh}(n,F)$, is the maximum…

Combinatorics · Mathematics 2023-12-20 Addisu Paulos

This paper constructs a planar graph $G_1$ such that for any subgraph $H$ of $G_1$ with maximum degree $\Delta(H) \le 3$, $G_1-E(H)$ is not $3$-choosable, and a planar graph $G_2$ such that for any star forest $F$ in $G_2$, $G_2-E(F)$…

Combinatorics · Mathematics 2019-06-05 Ringi Kim , Seog-Jin Kim , Xuding Zhu

A Gallai coloring of a complete graph is an edge-coloring such that no triangle has all its edges colored differently. A Gallai $k$-coloring is a Gallai coloring that uses $k$ colors. Given a graph $H$ and an integer $k\geq 1$, the…

Combinatorics · Mathematics 2019-10-29 Zi-Xia Song , Bing Wei , Fangfang Zhang , Qinghong Zhao

This work discusses the Alon-Tarsi number of line graphs and total graphs. In addition, we also discuss the Alon-Tarsi number of some Erdos-Faber-Lovasz (EFL) graphs.

Combinatorics · Mathematics 2024-01-01 S. Prajnanaswaroopa

A star edge coloring of a graph $G$ is a proper edge coloring of $G$ such that every path and cycle of length four in $G$ uses at least three different colors. The star chromatic index of $G$, is the smallest integer $k$ for which $G$…

Combinatorics · Mathematics 2021-03-03 Marzieh Vahid Dastjerdi

Given two graphs $G$ and $H$, the $k$-colored Gallai-Ramsey number $gr_k(G : H)$ is defined to be the minimum integer $n$ such that every $k$-coloring of the complete graph on $n$ vertices contains either a rainbow copy of $G$ or a…

Combinatorics · Mathematics 2018-11-16 Xihe Li , Ligong Wang

A $k$-cycle in a graph is a cycle of length $k.$ A graph $G$ of order $n$ is called edge-pancyclic if for every integer $k$ with $3\le k\le n,$ every edge of $G$ lies in a $k$-cycle. It seems difficult to determine the minimum size $f(n)$…

Combinatorics · Mathematics 2024-10-16 Chengli Li , Feng Liu , Xingzhi Zhan

Given two graphs $G$ and $H$ and a positive integer $k$, the $k$-color Gallai-Ramsey number, denoted by $gr_{k}(G : H)$, is the minimum integer $N$ such that for all $n \geq N$, every $k$-coloring of the edges of $K_{n}$ contains either a…

Combinatorics · Mathematics 2021-06-22 Zhao Wang , Yaping Mao , Colton Magnant , Ingo Sciermeyer , Jinyu Zou
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