activity
20102023
most citedOn the Chromatic Number of for Small Values of

4 citations · 5 across the 7 of their papers we have counts for

collaborators

7 papers

math.CO2023

A Lower Bound for R(5,6)

Geoffrey Exoo

The known lower bound for the the classical Ramsey number is improved from to . The method used to construct the graph is a simple variant of computational method…

math.CO2023

Attainable bounds for algebraic connectivity and maximally-connected regular graphs

Geoffrey Exoo, Theodore Kolokolnikov, Jeanette Janssen +1

We derive attainable upper bounds on the algebraic connectivity (spectral gap) of a regular graph in terms of its diameter and girth. This bound agrees with the well-known Alon-Bop…

math.CO2023

On large regular (1,1,k)-mixed graphs

C. Dalfó, G. Erskine, G. Exoo +4

An -mixed graph has every vertex with undirected degree , directed in- and out-degree , and diameter . In this paper, we study the case , proposing som…

math.CO2023

A 5-chromatic same-distance graph in the hyperbolic plane

Geoffrey Exoo, Dan Ismailescu

The chromatic number of the plane problem asks for the minimum number of colors so that each point of the plane can be assigned a single color with the property that no two points…

math.CO20144 cited

On the Chromatic Number of for Small Values of

Geoffrey Exoo, Dan Ismailescu

The lower bound for the chromatic number of is improved for $n = 6, 7, 10, 11, 12, 13 \mbox{ and } 14$.

math.CO2014

Three Graphs and the Erdős-Gyárfás Conjecture

Geoffrey Exoo

Three graphs related to the \EGC\, are presented. The graphs are derived from the Buckyball, the Petersen graph, and the Tutte-Coxeter graph. The first graph is a partial answer to…