arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1304.7352cond-mat.stat-mech
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如何估计超过10^100次的自我回避行走次数?使用随机游走

How to estimate the number of self-avoiding walks over 10^100? Use random walks

Nobu C. Shirai, Macoto Kikuchi

摘要:

计算格上N步自避免游动的个数是计数组合学中最困难的问题之一。然而,一旦我们放弃计算它们的确切数量,我们就有机会将统计力学的强大计算方法应用于这个问题。在本文中,我们开发了一个统计计数方法的SAW使用多规范蒙特卡罗方法。该方法的一个关键部分是将SAW的配置空间扩展为随机游走,其确切数量是已知的。使用这种方法,我们估计了一个正方形晶格,c_N,N=256的N-步SAW的数量。c_256的值是5.6(1)*10^108(括号中的数字是最后一位数字的统计误差),这大于一个古戈尔(10^100)。

英文摘要:

Counting the number of N-step self-avoiding walks (SAWs) on a lattice is one of the most difficult problems of enumerative combinatorics. Once we give up calculating the exact number of them, however, we have a chance to apply powerful computational methods of statistical mechanics to this problem. In this paper, we develop a statistical enumeration method for SAWs using the multicanonical Monte Carlo method. A key part of this method is to expand the configuration space of SAWs to random walks, the exact number of which is known. Using this method, we estimate a number of N-step SAWs on a square lattice, c_N, up to N=256. The value of c_256 is 5.6(1)*10^108 (the number in the parentheses is the statistical error of the last digit) and this is larger than one googol (10^100).

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。

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