Volume XXVIII

VOL XXVIII

Geombinatorics Quarterly

Issue 1 (July 2018)

Editors Page   4
New Essays    
Progress in My Favorite Open Problem of Mathematics, Chromatic
Number of the Plane: An Étude in Five Movements 
By Alexander Soifer  5
The Chromatic Number of the Plane Is at least 5 By Aubrey D.N.J. de Grey 18
Computing Small Unit-Distance Graphs with Chromatic
Number 5
By Marijn J.H. Heule 32
The Hadwiger-Nelson problem with two
forbidden distances
By Geoffrey Exoo and Dan Ismailescu 51
     
Recent Books   69

Issue 2 (October 2018)

Editors Page   76
New Essays    
The Chromatic Number of  The Taxicab Plane By John Donnelly 77
A note on the clique chromatic number of geometric graphs  By Jacob FoxJános Pach, and Andrew Suk 83
Extensions of Möbius-Kantor Configurations By J. Lanyon and R. Padmanabhan 93
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
 By Olga Kosheleval and Vladik Kreinovich 99
Truth, Like Water, Finds Its Way Out By Alexander Soifer 106
Revisiting Bodies having Constant HA-Measurements By Joseph Zaks 112

Issue 3 (January 2019)

Editors 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 Sarah 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. BurgerElie Feder, and Heiko Harborth 150

Issue 4 (April 2019)

Editors Page   176
New Essays    
Avoiding monochromatic configurations in the multi-colored plane By Seung Hwan AnDan Ismailescu, and Kwon Il Ko   177
On the Independence Numbers of the Van der Waerden and cyclic Van der Waerden Hypergraphs W(k; t) and Wc(k; t) when and Are Powers of the Same Prime By Peter Johnson and Zechun Yang  2
Tiling the plane with equilateral triangles By János Pach and Gábor Tardo   24
Chromatic Problems and Prizes By Alexander Soifer    33
Revisiting the 2Neighborly d-simplices in Ed By Joseph Zaks 37
Subscription Form   43