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Some globally determined classes of graphs

Ivica Bošnjak, Rozália Madarász (2018)

Czechoslovak Mathematical Journal

For a class of graphs we say that it is globally determined if any two nonisomorphic graphs from that class have nonisomorphic globals. We will prove that the class of so called CCB graphs and the class of finite forests are globally determined.

Some graphic uses of an even number of odd nodes

Kathie Cameron, Jack Edmonds (1999)

Annales de l'institut Fourier

Vertex-degree parity in large implicit “exchange graphs” implies some EP theorems asserting the existence of a second object without evidently providing a polytime algorithm for finding a second object.

Some graphs determined by their (signless) Laplacian spectra

Muhuo Liu (2012)

Czechoslovak Mathematical Journal

Let W n = K 1 C n - 1 be the wheel graph on n vertices, and let S ( n , c , k ) be the graph on n vertices obtained by attaching n - 2 c - 2 k - 1 pendant edges together with k hanging paths of length two at vertex v 0 , where v 0 is the unique common vertex of c triangles. In this paper we show that S ( n , c , k ) ( c 1 , k 1 ) and W n are determined by their signless Laplacian spectra, respectively. Moreover, we also prove that S ( n , c , k ) and its complement graph are determined by their Laplacian spectra, respectively, for c 0 and k 1 .

Some interpretations of the ( k , p ) -Fibonacci numbers

Natalia Paja, Iwona Włoch (2021)

Commentationes Mathematicae Universitatis Carolinae

In this paper we consider two parameters generalization of the Fibonacci numbers and Pell numbers, named as the ( k , p ) -Fibonacci numbers. We give some new interpretations of these numbers. Moreover using these interpretations we prove some identities for the ( k , p ) -Fibonacci numbers.

Some maximum multigraphs and edge/vertex distance colourings

Zdzisław Skupień (1995)

Discussiones Mathematicae Graph Theory

Shannon-Vizing-type problems concerning the upper bound for a distance chromatic index of multigraphs G in terms of the maximum degree Δ(G) are studied. Conjectures generalizing those related to the strong chromatic index are presented. The chromatic d-index and chromatic d-number of paths, cycles, trees and some hypercubes are determined. Among hypercubes, however, the exact order of their growth is found.

Some new classes of graceful Lobsters obtained from diameter four trees

Debdas Mishra, Pratima Panigrahi (2010)

Mathematica Bohemica

We observe that a lobster with diameter at least five has a unique path H = x 0 , x 1 , ... , x m with the property that besides the adjacencies in H both x 0 and x m are adjacent to the centers of at least one K 1 , s , where s > 0 , and each x i , 1 i m - 1 , is adjacent at most to the centers of some K 1 , s , where s 0 . This path H is called the central path of the lobster. We call K 1 , s an even branch if s is nonzero even, an odd branch if s is odd and a pendant branch if s = 0 . In the existing literature only some specific classes of lobsters have been found...

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