Title
Ramsey Games Against a One-Armed Bandit
Abstract
We study the following one-person game against a random graph process: the Player's goal is to $2$-colour a random sequence of edges $e_1,e_2,\dots$ of a complete graph on $n$ vertices, avoiding a monochromatic triangle for as long as possible. The game is over when a monochromatic triangle is created. The online version of the game requires that the Player should colour each edge as it comes, before looking at the next edge.While it is not hard to prove that the expected length of this game is about $n^{4/3}$, the proof of the upper bound suggests the following relaxation: instead of colouring online, the random graph is generated in only two rounds, and the Player colours the edges of the first round before the edges of the second round are thrown in. Given the size of the first round, how many edges can there be in the second round for the Player to be likely to win? In the extreme case, when the first round consists of a random graph with $cn^{3/2}$ edges, where $c$ is a positive constant, we show that the Player can win with high probability only if constantly many edges are generated in the second round.
Year
DOI
Venue
2003
10.1017/S0963548303005881
Combinatorics, Probability & Computing
Keywords
Field
DocType
following one-person game,complete graph,random graph,colouring online,ramsey games,monochromatic triangle,online version,next edge,random graph process,following relaxation,random sequence,one-armed bandit
Discrete mathematics,Strength of a graph,Combinatorics,Multigraph,Path (graph theory),Cycle graph,Mixed graph,Multiple edges,Mathematics,Complement graph,Path graph
Journal
Volume
Issue
ISSN
12
6
0963-5483
Citations 
PageRank 
References 
24
3.38
7
Authors
5
Name
Order
Citations
PageRank
Ehud Friedgut144038.93
Yoshiharu Kohayakawa247764.87
Vojtěch Rödl3887142.68
Andrzej Rucińskiandemory4243.38
Prasad Tetali5988100.91