54 research outputs found

    Regular graphs of odd degree are antimagic

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    An antimagic labeling of a graph GG with mm edges is a bijection from E(G)E(G) to {1,2,,m}\{1,2,\ldots,m\} such that for all vertices uu and vv, the sum of labels on edges incident to uu differs from that for edges incident to vv. Hartsfield and Ringel conjectured that every connected graph other than the single edge K2K_2 has an antimagic labeling. We prove this conjecture for regular graphs of odd degree.Comment: 5 page

    An Inductive Approach to Strongly Antimagic Labelings of Graphs

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    An antimagic labeling for a graph GG with mm edges is a bijection f:E(G){1,2,,m}f: E(G) \to \{1, 2, \dots, m\} so that ϕf(u)ϕf(v)\phi_f(u) \neq \phi_f(v) holds for any pair of distinct vertices u,vV(G)u, v \in V(G), where ϕf(x)=xef(e)\phi_f(x) = \sum_{x \in e} f(e). A strongly antimagic labeling is an antimagic labeling with an additional condition: For any u,vV(G)u, v \in V(G), if deg(u)>deg(v)\deg(u) > \deg(v), then ϕf(u)>ϕf(v)\phi_f(u) > \phi_f(v). A graph GG is strongly antimagic if it admits a strongly antimagic labeling. We present inductive properties of strongly antimagic labelings of graphs. This approach leads to simplified proofs that spiders and double spiders are strongly antimagic, previously shown by Shang [Spiders are antimagic, Ars Combinatoria, 118 (2015), 367--372] and Huang [Antimagic labeling on spiders, Master's Thesis, Department of Mathematics, National Taiwan University, 2015], and by Chang, Chin, Li and Pan [The strongly antimagic labelings of double spiders, Indian J. Discrete Math. 6 (2020), 43--68], respectively. We fix a subtle error in [The strongly antimagic labelings of double spiders, Indian J. Discrete Math. 6 (2020), 43--68]. Further, we prove certain level-wise regular trees, cycle spiders and cycle double spiders are all strongly antimagic

    Group-antimagic Labelings of Multi-cyclic Graphs

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    Let AA be a non-trivial abelian group. A connected simple graph G=(V,E)G = (V, E) is AA-\textbf{antimagic} if there exists an edge labeling f:E(G)A\{0}f: E(G) \to A \backslash \{0\} such that the induced vertex labeling f+:V(G)Af^+: V(G) \to A, defined by f+(v)=Σf^+(v) = \Sigma {f(u,v):(u,v)E(G)}\{f(u,v): (u, v) \in E(G) \}, is a one-to-one map. The \textit{integer-antimagic spectrum} of a graph GG is the set IAM(G)={k:G is Zk-antimagic and k2}(G) = \{k: G \textnormal{ is } \mathbb{Z}_k\textnormal{-antimagic and } k \geq 2\}. In this paper, we analyze the integer-antimagic spectra for various classes of multi-cyclic graphs

    SOME RESULTS OF LABELING ON BROOM GRAPH

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    A Broom Graph Bn,d  is a graph of n vertices, which have a path P with d vertices and (n-d) pendant vertices, all of these being adjacent to either the origin u or the terminus v of the path P. Here we consider various labeling on Broom graph such as Cordial labeling, Antimagic labeling and b-coloring. &nbsp

    A SURVEY OF DISTANCE MAGIC GRAPHS

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    In this report, we survey results on distance magic graphs and some closely related graphs. A distance magic labeling of a graph G with magic constant k is a bijection l from the vertex set to {1, 2, . . . , n}, such that for every vertex x Σ l(y) = k,y∈NG(x) where NG(x) is the set of vertices of G adjacent to x. If the graph G has a distance magic labeling we say that G is a distance magic graph. In Chapter 1, we explore the background of distance magic graphs by introducing examples of magic squares, magic graphs, and distance magic graphs. In Chapter 2, we begin by examining some basic results on distance magic graphs. We next look at results on different graph structures including regular graphs, multipartite graphs, graph products, join graphs, and splitting graphs. We conclude with other perspectives on distance magic graphs including embedding theorems, the matrix representation of distance magic graphs, lifted magic rectangles, and distance magic constants. In Chapter 3, we study graph labelings that retain the same labels as distance magic labelings, but alter the definition in some other way. These labelings include balanced distance magic labelings, closed distance magic labelings, D-distance magic labelings, and distance antimagic labelings. In Chapter 4, we examine results on neighborhood magic labelings, group distance magic labelings, and group distance antimagic labelings. These graph labelings change the label set, but are otherwise similar to distance magic graphs. In Chapter 5, we examine some applications of distance magic and distance antimagic labeling to the fair scheduling of tournaments. In Chapter 6, we conclude with some open problems
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