Some results on graphs with at most two positive eigenvalues.
Petrović, Miroslav (1991)
Publications de l'Institut Mathématique. Nouvelle Série
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Petrović, Miroslav (1991)
Publications de l'Institut Mathématique. Nouvelle Série
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Vladislav Bína, Jiří Přibil (2015)
Commentationes Mathematicae Universitatis Carolinae
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The paper brings explicit formula for enumeration of vertex-labeled split graphs with given number of vertices. The authors derive this formula combinatorially using an auxiliary assertion concerning number of split graphs with given clique number. In conclusion authors discuss enumeration of vertex-labeled bipartite graphs, i.e., a graphical class defined in a similar manner to the class of split graphs.
Amanda Niedzialomski (2016)
Discussiones Mathematicae Graph Theory
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For k ∈ ℤ+ and G a simple, connected graph, a k-radio labeling f : V (G) → ℤ+ of G requires all pairs of distinct vertices u and v to satisfy |f(u) − f(v)| ≥ k + 1 − d(u, v). We consider k-radio labelings of G when k = diam(G). In this setting, f is injective; if f is also surjective onto {1, 2, . . . , |V (G)|}, then f is a consecutive radio labeling. Graphs that can be labeled with such a labeling are called radio graceful. In this paper, we give two results on the existence of radio...
Ľubomír Šoltés (1990)
Acta Universitatis Carolinae. Mathematica et Physica
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X. Shen, Y. Hou, I. Gutman, X. Hui (2010)
Bulletin, Classe des Sciences Mathématiques et Naturelles, Sciences mathématiques
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A. K. Dewdney, Frank Harary (1976)
Czechoslovak Mathematical Journal
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Gliviak, Ferdinand, Kyš, P. (1997)
Acta Mathematica Universitatis Comenianae. New Series
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Peter Hudák, Mária Maceková, Tomáš Madaras, Pavol Široczki (2016)
Discussiones Mathematicae Graph Theory
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A graph H is defined to be light in a graph family 𝒢 if there exist finite numbers φ(H, 𝒢) and w(H, 𝒢) such that each G ∈ 𝒢 which contains H as a subgraph, also contains its isomorphic copy K with ΔG(K) ≤ φ(H, 𝒢) and ∑x∈V(K) degG(x) ≤ w(H, 𝒢). In this paper, we investigate light graphs in families of plane graphs of minimum degree 2 with prescribed girth and no adjacent 2-vertices, specifying several necessary conditions for their lightness and providing sharp bounds on φ and w...