Title
Voronoi tessellations in the CRT and continuum random maps of finite excess.
Abstract
Given a large graph G and k agents on this graph, we consider the Voronoi tessellation induced by the graph distance. Each agent gets control of the portion of the graph that is closer to itself than to any other agent. We study the limit law of the vector Vor := (V1/n, V2/n,..., Vk/n), whose i'th coordinate records the fraction of vertices of G controlled by the i'th agent, as n tends to infinity. We show that if G is a uniform random tree, and the agents are placed uniformly at random, the limit law of Vor is uniform on the (k − 1)-dimensional simplex. In particular, when k = 2, the two agents each get a uniform random fraction of the territory. In fact, we prove the result directly on the Brownian continuum random tree (CRT), and we also prove the same result for a "higher genus" analogue of the CRT that we call the continuum random unicellular map, indexed by a genus parameter g ≥ 0. As a key step of independent interest, we study the case when G is a random planar embedded graph with a finite number of faces. The main idea of the proof is to show that Vor has the same distribution as another partition of mass Int := (I1/n,I2/n, ..., Ik/n) where Ij is the contour length separating the i-th agent from the next one in clockwise order around the graph.
Year
DOI
Venue
2018
10.5555/3174304.3175330
SODA '18: Symposium on Discrete Algorithms New Orleans Louisiana January, 2018
Field
DocType
ISBN
Random tree,Discrete mathematics,Combinatorics,Finite set,Vertex (geometry),Computer science,Distance,Simplex,Voronoi diagram,Partition (number theory),Brownian motion
Conference
978-1-61197-503-1
Citations 
PageRank 
References 
0
0.34
0
Authors
5
Name
Order
Citations
PageRank
Louigi Addario-Berry112722.22
Omer Angel23715.53
Guillaume Chapuy37311.25
Éric Fusy419821.95
Christina Goldschmidt500.34