activity
20092023
most citedOn the Chromatic Number of for Small Values of

4 citations · 14 across the 16 of their papers we have counts for

collaborators

16 papers

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.CO2021★ 3 cited

The chromatic number of the Minkowski plane -- the regular polygon case

Geoffrey Exoo, David Fisher, Dan Ismailescu

The Hadwiger-Nelson 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 unit-distance…

math.CO2021

On the maximum area of inscribed polygons

Dan Ismailescu, Min Jung Kim, Eric Wang

Given a convex -gon and a positive integer such that , let denote the largest area convex -gon contained in . We are interested in the minimum v…

math.CO2020

An improved upper bound for the size of the sphere of influence graph

Dan Ismailescu, Sung Hoon Kim, Taeyang David Park

Let be a set of points in the plane. For each , let be the closed circular disk centered at with radius equal to the distance from to its closest neig…

math.CO2020

Outdegree conditions forcing short cycles in digraphs

Dan Ismailescu, Joonsoo Lee, Andrew Yang

Given a positive integer , let be the smallest positive constant with the following property: \emph{ Every simple directed graph on vertices all whose outd…

math.CO2019★ 2 cited

A -chromatic two-distance graph in the plane

Geoffrey Exoo, Dan Ismailescu

We prove that if one colors each point of the Euclidean plane with one of five colors, then there exist two points of the same color that are either distance or distance ap…