arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1012.3720math.CO
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正方形格上闭随机游动按面积的Enumeration

Enumeration of closed random walks in the square lattice according to their areas

Morteza Mohammad-Noori

摘要:

本文研究了长度为$n$,起始和终止于原点的闭游动的面积分布。本文推广了正方形格上行走面积的概念,并通过一个简单的论证证明了这个新概念的实用性。得出结论:在特殊群环$R[x,y,z]$中,长度$n$和面积$s$的步数等于表达式$(x+x^{-1}+y+y^{-1})^n$中$z^s$的系数.最后给出了计算这些值的多项式时间算法。最后,将所提出的算法和实现结果与前人的工作进行了比较.

英文摘要:

We study the area distribution of closed walks of length $n$, beginning and ending at the origin. The concept of area of a walk in the square lattice is generalized and the usefulness of the new concept is demonstrated through a simple argument. It is concluded that the number of walks of length $n$ and area $s$ equals to the coefficient of $z^s$ in the expression $(x+x^{-1}+y+y^{-1})^n$, where the calculations are performed in a special group ring $R[x,y,z]$. A polynomial time algorithm for calculating these values, is then concluded. Finally, the provided algorithm and the results of implementation are compared with previous works.

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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