论文标题
通过轮廓变形在2+1d XY模型中以有限密度的指数减小符号问题的指数降低
Exponential reduction of the sign problem at finite density in the 2+1D XY model via contour deformations
论文作者
论文摘要
我们在变形的集成歧管上研究了非零化学势$μ$的2+1维XY模型，目的是减轻其符号问题。我们调查了一些变形的建议，并在标准重新加权方法方面大大提高了符号问题的严重性。我们提供了数值证据，表明符号问题的减少在$μ^2 $和空间体积中都是指数级的。我们还为基于重新加权的优化过程提供了一种新的方法，从而明智地降低了其计算成本。
We study the 2+1 dimensional XY model at nonzero chemical potential $μ$ on deformed integration manifolds, with the aim of alleviating its sign problem. We investigate several proposals for the deformations, and considerably improve on the severity of the sign problem with respect to standard reweighting approaches. We present numerical evidence that the reduction of the sign problem is exponential both in $μ^2$ and in the spatial volume. We also present a new approach to the optimization procedure based on reweighting, that sensibly reduces its computational cost.
