PHASE TRANSITION FOR THE MIXING TIME OF THE GLAUBER DYNAMICS FOR COLORING REGULAR TREES

• 成果类型: Article
• 署名作者: Tetali, Prasad; Vera, Juan C.; Vigoda, Eric; Yang, Linji
• 署名单位: University System of Georgia; Georgia Institute of Technology; University System of Georgia; Georgia Institute of Technology; Tilburg University
• 刊物名称: ANNALS OF APPLIED PROBABILITY
• ISSN/ISSBN: 1050-5164
• DOI: 10.1214/11-AAP833
• 发表日期: 2012
• 页码: 2210-2239
• 关键词: Bounds

摘要

We prove that the mixing time of the Glauber dynamics for random k-colorings of the complete tree with branching factor b undergoes a phase transition at k = b(1 + o(b)(1))/In b. Our main result shows nearly sharp bounds on the mixing time of the dynamics on the complete tree with n vertices for k = Cb/In b colors with constant C. For C >= 1 we prove the mixing time is O(n(1+ob(1)) In n). On the other side, for C < 1 the mixing time experiences a slowing down; in particular, we prove it is O(n(1/C+ob(1)) In n) and Omega (n(1/C-ob(1))). The critical point C = 1 is interesting since it coincides (at least up to first order) with the so-called reconstruction threshold which was recently established by Sly. The reconstruction threshold has been of considerable interest recently since it appears to have close connections to the efficiency of certain local algorithms, and this work was inspired by our attempt to understand these connections in this particular setting.