Table of Contents | Volume XXVIII July 2018 – April 2019

Geombinatorics

A quarterly journal on open problems of combinatorial and discrete geometry and related areas.

July 2018 – April 2019

Issue 1   Issue 2   Issue 3    Issue 4 


Issue 1 (July 2018)


CONTENTS XXVIII (1)

Editor’s Page………………….…………………………………..4

New Essays

Progress in My Favorite Open Problem of Mathematics, Chromatic
Number of the Plane: An Étude in Five Movements ………..……5
by Alexander Soifer

 

The Chromatic Number of the Plane Is at least 5 ………….…….18
by Aubrey D.N.J. de Grey

 

Computing Small Unit-Distance Graphs with Chromatic
Number 5…………………………………………………………..32
by Marijn J.H. Heule

 

The Hadwiger-Nelson problem with two
forbidden distances……………………………………………….51
by Geoffrey Exoo and Dan Ismailescu

Recent Books……………………………..………….………69


Issue 2 (October 2018)


CONTENTS XXVIII (2)

Editor’s Page………………….…………………………………..76

New Essays

The Chromatic Number of  The Taxicab Plane ………..……77
by John Donnelly

 

A note on the clique chromatic number of geometric graphs …….83
by Jacob Fox, János Pach, and Andrew Suk

 

Extensions of Möbius-Kantor Configurations…………………………………………………………..93
by J. Lanyon and R. Padmanabhan

 

Why Asset-Based Approach to Teaching Is More Effective
than 
the Usual Deficit-Based Approach, and Why the New
Approach 
Is Not Easy to Implement: A Simple Geometric Explanation……………………….99
by Olga Kosheleval and Vladik Kreinovich

 

Truth, Like Water, Finds Its Way Out…………………………………………………………….106
by Alexander Soifer

 

Revisiting Bodies having Constant HA-Measurements…………………………………….112
by Joseph Zaks

 


Issue 3 (January 2019)


CONTENTS XXVIII(3)

Editor’s Page………………….……………………………….120

New Essays

[4,3]-Configurations with Many Symmetries
by Branko Grünbaum

Branko Grünbaum, a Fantastic Father as well as Renowned Mathematician
by Rami Grunbaum with Daniel Grünbaum……………….121

Inseparability
by Sara Zaks…………..…………………………………..…….124

Branko
by Moshe Rosenfeld………..………………………………….127

Branko Grünbaum in Many Dimensions
by Matthew Kahle……………………………………………132

Branko, My Teacher, Collaborator, and Friend
by Alexander Soifer………..………………………………..139

Numbers of Crossings for Cycle Graphs
by Alewyn P. Burger, Elie Feder, and Heiko Harborth ……150


Issue 4 (April 2019)