arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1009.4802math.COmath.PR
收藏

转子在一般树上行走

Rotor walks on general trees

Omer Angel, Alexander E. Holroyd

摘要:

图上的转子游动是随机游动的确定性模拟。每个顶点都配备了一个转子,它在连续访问时以固定的循环顺序将步行者路由到相邻的顶点。考虑转子在无限根有根树上行走,每次逃逸到无穷远后从根重新开始。我们证明了逃逸到无穷大的限制比例等于逃逸概率随机游动,提供了许多转子发送的沃克最初对根。为了i.i.d.随机初始转子方向的规则树,逃逸的限制比例是零或随机游动逃逸概率,并经历一个不连续的相变之间的分布是不同的。在临界情况下,没有逃脱,但步行者到根的最大距离随着访问根的次数成倍增长。我们还证明了存在有界度的树,其逃逸的比例最终超过任意大的o(1)函数的逃逸概率。没有更大的差异是可能的,而对于规则树,差异最多是对数的。

英文摘要:

The rotor walk on a graph is a deterministic analogue of random walk. Each vertex is equipped with a rotor, which routes the walker to the neighbouring vertices in a fixed cyclic order on successive visits. We consider rotor walk on an infinite rooted tree, restarted from the root after each escape to infinity. We prove that the limiting proportion of escapes to infinity equals the escape probability for random walk, provided only finitely many rotors send the walker initially towards the root. For i.i.d. random initial rotor directions on a regular tree, the limiting proportion of escapes is either zero or the random walk escape probability, and undergoes a discontinuous phase transition between the two as the distribution is varied. In the critical case there are no escapes, but the walker's maximum distance from the root grows doubly exponentially with the number of visits to the root. We also prove that there exist trees of bounded degree for which the proportion of escapes eventually exceeds the escape probability by arbitrarily large o(1) functions. No larger discrepancy is possible, while for regular trees the discrepancy is at most logarithmic.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑