2 citations · 4 across the 5 of their papers we have counts for
4 papers · 1 filter
Extremal diameters of 3-coloring graphs of trees
Shamil Asgarli, Sara Krehbiel, Simon MacLean +1
Given a tree , its 3-coloring graph has as vertices the proper 3-colorings of , with edges joining colorings that differ at exactly one vertex. We call the…
Combinatorial reciprocity for non-intersecting paths
Sam Hopkins, Gjergji Zaimi
We prove a combinatorial reciprocity theorem for the enumeration of non-intersecting paths in a linearly growing sequence of acyclic planar networks. We explain two applications of…
Restricted Birkhoff polytopes and Ehrhart period collapse
Per Alexandersson, Sam Hopkins, Gjergji Zaimi
We show that the polytopes obtained from the Birkhoff polytope by imposing additional inequalities restricting the "longest increasing subsequence" have Ehrhart quasi-polynomials w…
Frankl's Conjecture for subgroup lattices
Alireza Abdollahi, Russ Woodroofe, Gjergji Zaimi
We show that the subgroup lattice of any finite group satisfies Frankl's Union-Closed Conjecture. We show the same for all lattices with a modular coatom, a family which includes a…