Title
Distributed Symmetry Breaking in Sampling (Optimal Distributed Randomly Coloring with Fewer Colors).
Abstract
examine the problem of almost-uniform sampling proper $q$-colorings of a graph whose maximum degree is $Delta$. A famous result, discovered independently by Jerrum(1995) and Salas and Sokal(1997), is that, assuming $q u003e (2+delta) Delta$, the Glauber dynamics (a.k.a.~single-site dynamics) for this problem has mixing time $O(n log n)$, where $n$ is the number of vertices, and thus provides a nearly linear time sampling algorithm for this problem. A natural question is the extent to which this algorithm can be parallelized. Previous work Feng, Sun and Yin [PODCu002717] has shown that a $O(Delta log n)$ time parallelized algorithm is possible, and that $Omega(log n)$ time is necessary. We give a distributed sampling algorithm, which we call the Lazy Local Metropolis Algorithm, that achieves an optimal parallelization of this classic algorithm. It improves its predecessor, the Local Metropolis algorithm of Feng, Sun and Yin [PODCu002717], by introducing a step of distributed symmetry breaking that helps the mixing of the distributed sampling algorithm. For sampling almost-uniform proper $q$-colorings of graphs $G$ on $n$ vertices, we show that the Lazy Local Metropolis algorithm achieves an optimal $O(log n)$ mixing time if either of the following conditions is true for an arbitrary constant $deltau003e0$: (1) $qge(2+delta)Delta$, on general graphs with maximum degree $Delta$; (2) $q geq (alpha^* + delta)Delta$, where $alpha^* approx 1.763$ satisfies $alpha^* = mathrm{e}^{1/alpha^*}$, on graphs with sufficiently large maximum degree $Deltage Delta_0(delta)$ and girth at least $9$.
Year
Venue
Field
2018
arXiv: Data Structures and Algorithms
Binary logarithm,Discrete mathematics,Combinatorics,Vertex (geometry),Metropolis–Hastings algorithm,Symmetry breaking,Omega,Sampling (statistics),Degree (graph theory),Time complexity,Mathematics
DocType
Volume
Citations 
Journal
abs/1802.06953
3
PageRank 
References 
Authors
0.40
17
3
Name
Order
Citations
PageRank
Weiming Feng131.41
Thomas P. Hayes265954.21
Yitong Yin321323.42