All a b c d e f g h i j k l m n o p q r s t u v w x y z Other

Page 1

Displaying 1 – 13 of 13

Showing per page

New edge neighborhood graphs

Ali A. Ali, Salar Y. Alsardary (1997)

Czechoslovak Mathematical Journal

Let G be an undirected simple connected graph, and e = u v be an edge of G . Let N G ( e ) be the subgraph of G induced by the set of all vertices of G which are not incident to e but are adjacent to u or v . Let 𝒩 e be the class of all graphs H such that, for some graph G , N G ( e ) ≅ H for every edge e of G . Zelinka [3] studied edge neighborhood graphs and obtained some special graphs in 𝒩 e . Balasubramanian and Alsardary [1] obtained some other graphs in 𝒩 e . In this paper we given some new graphs in 𝒩 e .

New proof of a characterization of geodetic graphs

Ladislav Nebeský (2002)

Czechoslovak Mathematical Journal

In [3], the present author used a binary operation as a tool for characterizing geodetic graphs. In this paper a new proof of the main result of the paper cited above is presented. The new proof is shorter and simpler.

Nonempty intersection of longest paths in a graph with a small matching number

Fuyuan Chen (2015)

Czechoslovak Mathematical Journal

A maximum matching of a graph G is a matching of G with the largest number of edges. The matching number of a graph G , denoted by α ' ( G ) , is the number of edges in a maximum matching of G . In 1966, Gallai conjectured that all the longest paths of a connected graph have a common vertex. Although this conjecture has been disproved, finding some nice classes of graphs that support this conjecture is still very meaningful and interesting. In this short note, we prove that Gallai’s conjecture is true for...

Non-hyperbolicity in random regular graphs and their traffic characteristics

Gabriel Tucci (2013)

Open Mathematics

In this paper we prove that random d-regular graphs with d ≥ 3 have traffic congestion of the order O(n logd−13 n) where n is the number of nodes and geodesic routing is used. We also show that these graphs are not asymptotically δ-hyperbolic for any non-negative δ almost surely as n → ∞.

Note on independent sets of a graph

Jaroslav Ivančo (1994)

Mathematica Bohemica

Let the number of k -element sets of independent vertices and edges of a graph G be denoted by n ( G , k ) and m ( G , k ) , respectively. It is shown that the graphs whose every component is a circuit are the only graphs for which the equality n ( G , k ) = m ( G , k ) is satisfied for all values of k .

Currently displaying 1 – 13 of 13

Page 1