论文标题
两点相关器计算的多级性能的数值和理论研究
A numerical and theoretical study of multilevel performance for two-point correlator calculations
论文作者
论文摘要
已经使用Ising模型对多级算法的性能进行了研究，并在一系列温度下进行了模拟。数值结果表明，随着相关长度相对于晶格的大小而增加，该系统中多级的性能会恶化。当相关长度小于晶格大小的十分之一时，系统中最长的相关器的统计误差会减少，而对于较长的相关长度，多级的统计误差比计算机时间等效的单级算法更差。概述了该性能缩放的理论模型，与数值结果相比，表现出非常出色的准确性。该理论模型可以应用于具有更复杂光谱的其他系统，以预测多级技术是否可能导致统计数据的改善。
An investigation of the performance of the multilevel algorithm in the approach to criticality has been undertaken using the Ising model, performing simulations across a range of temperatures. Numerical results show that the performance of multilevel in this system deteriorates as the correlation length is increased with respect to the lattice size. The statistical error of the longest correlator in the system is reduced in a multilevel setup when the correlation length is less than one-tenth of the lattice size, while for longer correlation lengths multilevel performs more poorly than a computer-time equivalent single level algorithm. A theoretical model of this performance scaling is outlined, and shows remarkable accuracy when compared to numerical results. This theoretical model may be applied to other systems with more complex spectra to predict if multilevel techniques are likely to result in improved statistics.
