Eccentricities in the flip-graphs of convex polygons
Abstract
The flip-graph of a convex polygon is the graph whose vertices are the triangulations of and whose edges correspond to flips between them. The eccentricity of a triangulation of is the largest possible distance in this graph from to any triangulation of . It is well known that, when all interior edges of are incident to the same vertex, the eccentricity of in the flip-graph of is exactly , where denotes the number of vertices of . Here, this statement is generalized to arbitrary triangulations. Denoting by the largest number of interior edges of incident to a vertex, it is shown that the eccentricity of in the flip-graph of is exactly , provided . Inversely, the eccentricity of a triangulation, when small enough, allows to recover the value of . More precisely, if , it is also shown that has eccentricity if and only if exactly of its interior edges are incident to a given vertex. When , bounds on the eccentricity of are also given and discussed.
Cite
@article{arxiv.1706.06456,
title = {Eccentricities in the flip-graphs of convex polygons},
author = {Lionel Pournin},
journal= {arXiv preprint arXiv:1706.06456},
year = {2019}
}
Comments
16 pages, 4 figures