English

Waiter-Client and Client-Waiter colourability games on a $k$-uniform hypergraph and the $k$-SAT game

Combinatorics 2016-07-11 v1

Abstract

Waiter-Client and Client-Waiter games are two-player, perfect information games, with no chance moves, played on a finite set (board) with special subsets known as the winning sets. Each round of the biased (1:q)(1:q) game begins with Waiter offering q+1q+1 previously unclaimed elements of the board to Client, who claims one. The qq elements remaining are then claimed by Waiter. If Client fully claims a winning set by the time all board elements have been offered, he wins in the Client-Waiter game and loses in the Waiter-Client game. We give an estimate for the threshold bias of the (1:q)(1:q) Waiter-Client and Client-Waiter versions of two different games: the non-2-colourability game, played on the complete kk-uniform hypergraph, and the kk-SAT game. In particular, we show that the unique value of qq at which the winner of the Client-Waiter version of the non-2-colourability game changes is 1n(nk)2k(1+ok(1))\frac{1}{n}\binom{n}{k}2^{-k(1+o_k(1))} and, for the Waiter-Client version, the corresponding value of qq is 1n(nk)2Θk(k)\frac{1}{n}\binom{n}{k}2^{\Theta_k(k)}. Additionally, we show that the threshold bias for the Waiter-Client and Client-Waiter versions of the kk-SAT game is 1n(nk)\frac{1}{n}\binom{n}{k} up to a factor that is exponential and polynomial in kk respectively. This shows that these games exhibit the "probabilistic intuition".

Keywords

Cite

@article{arxiv.1607.02258,
  title  = {Waiter-Client and Client-Waiter colourability games on a $k$-uniform hypergraph and the $k$-SAT game},
  author = {Wei En Tan},
  journal= {arXiv preprint arXiv:1607.02258},
  year   = {2016}
}

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16 pages