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相关论文: 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…

组合数学 · 数学 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…

组合数学 · 数学 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.

组合数学 · 数学 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…

组合数学 · 数学 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…

组合数学 · 数学 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…

组合数学 · 数学 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…

组合数学 · 数学 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.

组合数学 · 数学 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…

离散数学 · 计算机科学 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…

组合数学 · 数学 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…

组合数学 · 数学 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 $G$…

组合数学 · 数学 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…

组合数学 · 数学 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 $G_2$, $G_2-E(F)$…

组合数学 · 数学 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…

组合数学 · 数学 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.

组合数学 · 数学 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 $G$…

组合数学 · 数学 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…

组合数学 · 数学 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 $f(n)$…

组合数学 · 数学 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…

组合数学 · 数学 2021-06-22 Zhao Wang , Yaping Mao , Colton Magnant , Ingo Sciermeyer , Jinyu Zou
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