2016/11/11 by Sarah Cannon, Cannon, Sarah, David Levin +4 · 1 citation
Computer Science · Mathematics · #Advanced Combinatorial Mathematics #Cellular Automata and Applications #Combinatorics (math.CO) #Discrete Mathematics (cs.DM) #FOS: Computer and information sciences #FOS: Mathematics #Markov Chains and Monte Carlo Methods #Probability (math.PR) #Stochastic processes and statistical mechanics
paper · pdf · doi:10.48550/arxiv.1611.03636
openalex publication_date 2016/11/11 · openalex created_date 2022/08/20 · openalex updated_date 2026/07/28
We give the first polynomial upper bound on the mixing time of the edge-flip\nMarkov chain for unbiased dyadic tilings, resolving an open problem originally\nposed by Janson, Randall, and Spencer in 2002. A dyadic tiling of size n is a\ntiling of the unit square by n non-overlapping dyadic rectangles, each of area\n1/n, where a dyadic rectangle is any rectangle that can be written in the form\n[a2-s, (a+1)2-s] \× [b2-t, (b+1)2-t] for non-negative integers\na,b,s,t. The edge-flip Markov chain selects a random edge of the tiling and\nreplaces it with its perpendicular bisector if doing so yields a valid dyadic\ntiling. Specifically, we show that the relaxation time of the edge-flip Markov\nchain for dyadic tilings is at most O(n4.09), which implies that the mixing\ntime is at most O(n5.09). We complement this by showing that the relaxation\ntime is at least \Ω(n1.38), improving upon the previously best lower\nbound of \Ω(n\log n) coming from the diameter of the chain.\n