Results 31 to 40 of about 91 (73)
Decomposing tournaments into paths
Proceedings of the London Mathematical Society, Volume 121, Issue 2, Page 426-461, August 2020., 2020 Abstract We consider a generalisation of Kelly's conjecture which is due to Alspach, Mason, and Pullman from 1976. Kelly's conjecture states that every regular tournament has an edge decomposition into Hamilton cycles, and this was proved by Kühn and Osthus for large tournaments. The conjecture of Alspach, Mason, and Pullman asks for the minimum number
Allan Lo +3 more
wiley +1 more source
Untwisting 3‐strand torus knots
Bulletin of the London Mathematical Society, Volume 52, Issue 3, Page 429-436, June 2020., 2020 Abstract We prove that the signature bound for the topological 4‐genus of 3‐strand torus knots is sharp, using McCoy's twisting method. We also show that the bound is off by at most 1 for 4‐strand and 6‐strand torus knots, and improve the upper bound on the asymptotic ratio between the topological 4‐genus and the Seifert genus of torus knots from 2/3 ...
S. Baader, I. Banfield, L. Lewark
wiley +1 more source
Location of zeros for the partition function of the Ising model on bounded degree graphs
Journal of the London Mathematical Society, Volume 101, Issue 2, Page 765-785, April 2020., 2020 Abstract The seminal Lee–Yang theorem states that for any graph the zeros of the partition function of the ferromagnetic Ising model lie on the unit circle in C. In fact, the union of the zeros of all graphs is dense on the unit circle. In this paper, we study the location of the zeros for the class of graphs of bounded maximum degree d⩾3, both in the ...
Han Peters, Guus Regts
wiley +1 more source
The harmonic index for unicyclic and bicyclic graphs with given matching number
, 2015 The harmonic index of a graph G is defined as the sum of the weights 2 d.u/Cd.v/ of all edges uv of G, where d.u/ denotes the degree of a vertex u in G.
Lingping Zhong
semanticscholar +1 more source
Topological Indices of Para-line Graphs of V-Phenylenic Nanostructures
Open Mathematics, 2019 The degree-based topological indices are numerical graph invariants which are used to correlate the physical and chemical properties of a molecule with its structure.
Nadeem Imran +3 more
doaj +1 more source
Sharp Upper Bounds on the Clar Number of Fullerene Graphs
Discussiones Mathematicae Graph Theory, 2018 The Clar number of a fullerene graph with n vertices is bounded above by ⌊n/6⌋ − 2 and this bound has been improved to ⌊n/6⌋ − 3 when n is congruent to 2 modulo 6.
Gao Yang, Zhang Heping
doaj +1 more source
THE SECOND EDGE-WIENER INDEX OF SOME COMPOSITE GRAPHS
, 2014 In this paper we study the behavior of the second edge-Wiener index under the join and corona product of graphs. Results are applied for some classes of graphs such as suspensions, bottlenecks, and thorny graphs.
M. Azari, A. Iranmanesh
semanticscholar +1 more source
The Sanskruti index of trees and unicyclic graphs
Open Chemistry, 2019 The Sanskruti index of a graph G is defined as S(G)=∑uv∈E(G)sG(u)sG(v)sG(u)+sG(v)−23,$$\begin{align*}S(G)=\sum_{uv\in{}E(G)}{\left(\frac{s_G(u)s_G(v)}{s_G(u)+s_G(v)-2}\right)}^3, \end{align*}$$where sG(u) is the sum of the degrees of the neighbors of a ...
Deng Fei +6 more
doaj +1 more source
SCHULTZ AND GUTMAN INDICES FOR GRAPH COMPLEMENTS
, 2015 A graph G is said to have property (*) [4] if for every pair of its adjacent vertices u and v there exists a vertex w such that w is not adjacent to u and v.
S. Ramakrishnan, J. Babujee
semanticscholar +1 more source
Main Group Metal ChemistryFor a graph Q=(V,E){\mathbb{Q}}=\left({\mathbb{V}},{\mathbb{E}}), the transformation graph are defined as graphs with vertex set being V(Q)∪E(Q){\mathbb{V}}\left({\mathbb{Q}})\cup {\mathbb{E}}\left({\mathbb{Q}}) and edge set is described following ...
Ali Parvez +5 more
doaj +1 more source