scholarly journals Corrigendum to “Almost self-complementary factors of complete bipartite graphs” [Discrete Math. 167/168 (1997) 317–327]

2001 ◽  
Vol 232 (1-3) ◽  
pp. 195-197
Author(s):  
Dalibor Fronček
2014 ◽  
Vol 12 (12) ◽  
Author(s):  
Teresa Haynes ◽  
Michael Henning ◽  
Lucas Merwe ◽  
Anders Yeo

AbstractA graph is diameter-2-critical if its diameter is two and the deletion of any edge increases the diameter. Let G be a diameter-2-critical graph of order n. Murty and Simon conjectured that the number of edges in G is at most ⌊n 2/4⌋ and that the extremal graphs are the complete bipartite graphs K ⌊n/2⌋,⌊n/2⌉. Fan [Discrete Math. 67 (1987), 235–240] proved the conjecture for n ≤ 24 and for n = 26, while Füredi [J. Graph Theory 16 (1992), 81–98] proved the conjecture for n > n 0 where n 0 is a tower of 2’s of height about 1014. The conjecture has yet to be proven for other values of n. Let Δ denote the maximum degree of G. We prove the following maximum degree theorems for diameter-2-critical graphs. If Δ ≥ 0.7 n, then the Murty-Simon Conjecture is true. If n ≥ 2000 and Δ ≥ 0.6789 n, then the Murty-Simon Conjecture is true.


2021 ◽  
pp. 2142014
Author(s):  
Xiaoxue Gao ◽  
Shasha Li ◽  
Yan Zhao

For a graph [Formula: see text] and a set [Formula: see text] of size at least [Formula: see text], a path in [Formula: see text] is said to be an [Formula: see text]-path if it connects all vertices of [Formula: see text]. Two [Formula: see text]-paths [Formula: see text] and [Formula: see text] are said to be internally disjoint if [Formula: see text] and [Formula: see text]. Let [Formula: see text] denote the maximum number of internally disjoint [Formula: see text]-paths in [Formula: see text]. The [Formula: see text]-path-connectivity [Formula: see text] of [Formula: see text] is then defined as the minimum [Formula: see text], where [Formula: see text] ranges over all [Formula: see text]-subsets of [Formula: see text]. In [M. Hager, Path-connectivity in graphs, Discrete Math. 59 (1986) 53–59], the [Formula: see text]-path-connectivity of the complete bipartite graph [Formula: see text] was calculated, where [Formula: see text]. But, from his proof, only the case that [Formula: see text] was considered. In this paper, we calculate the situation that [Formula: see text] and complete the result.


2017 ◽  
Vol 340 (3) ◽  
pp. 481-493
Author(s):  
Ayineedi Venkateswarlu ◽  
Santanu Sarkar ◽  
Sai Mali Ananthanarayanan

1982 ◽  
Vol 25 (2) ◽  
pp. 187-206
Author(s):  
Yousef Alavi ◽  
Sabra S. Anderson ◽  
Gary Chartrand ◽  
S.F. Kapoor

A graph G, every vertex of which has degree at least three, is randomly 3-axial if for each vertex v of G, any ordered collection of three paths in G of length one with initial vertex v can be cyclically randomly extended to produce three internally disjoint paths which contain all the vertices of G. Randomly 3-axial graphs of order p > 4 are characterized for p ≢ 1 (mod 3), and are shown to be either complete graphs or certain regular complete bipartite graphs.


2021 ◽  
Vol 10 (4) ◽  
pp. 2115-2129
Author(s):  
P. Kandan ◽  
S. Subramanian

On the great success of bond-additive topological indices like Szeged, Padmakar-Ivan, Zagreb, and irregularity measures, yet another index, the Mostar index, has been introduced recently as a peripherality measure in molecular graphs and networks. For a connected graph G, the Mostar index is defined as $$M_{o}(G)=\displaystyle{\sum\limits_{e=gh\epsilon E(G)}}C(gh),$$ where $C(gh) \,=\,\left|n_{g}(e)-n_{h}(e)\right|$ be the contribution of edge $uv$ and $n_{g}(e)$ denotes the number of vertices of $G$ lying closer to vertex $g$ than to vertex $h$ ($n_{h}(e)$ define similarly). In this paper, we prove a general form of the results obtained by $Do\check{s}li\acute{c}$ et al.\cite{18} for compute the Mostar index to the Cartesian product of two simple connected graph. Using this result, we have derived the Cartesian product of paths, cycles, complete bipartite graphs, complete graphs and to some molecular graphs.


2007 ◽  
Vol 23 (3) ◽  
pp. 255-262 ◽  
Author(s):  
Jinquan Dong ◽  
Yanpei Liu

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