Institut für Physik, Humboldt-Universität zu Berlin, Newtonstr. 15, 12489 Berlin, Germany.
Phys Rev E. 2018 Jan;97(1-1):012119. doi: 10.1103/PhysRevE.97.012119.
We compute two- and three-point functions at criticality for the three-dimensional Ising universality class. To this end, we simulate the improved Blume-Capel model at the critical temperature on lattices of a linear size up to L=1600. As a check, also simulations of the spin-1/2 Ising model are performed. We find f_{σσε}=1.051(1) and f_{εεε}=1.533(5) for operator product expansion coefficients. These results are consistent with but less precise than those recently obtained by using the bootstrap method. An important ingredient in our simulations is a variance reduced estimator of N-point functions. Finite size corrections vanish with L^{-Δ_{ε}}, where L is the linear size of the lattice and Δ_{ε} is the scaling dimension of the leading Z_{2}-even scalar ε.
我们在三维伊辛临界类中计算了两点和三点函数。为此，我们在 lattices of a linear size up to L=1600 上模拟了改进的 Blume-Capel 模型在临界温度下的情况。作为检查，还对自旋为 1/2 的伊辛模型进行了模拟。我们发现算子乘积展开系数 f_{σσε}=1.051(1) 和 f_{εεε}=1.533(5)。这些结果与最近使用自举法得到的结果一致，但精度稍差。我们模拟的一个重要组成部分是 N 点函数的方差减小估计器。有限大小修正随 L^{-Δ_{ε}} 消失，其中 L 是晶格的线性大小，Δ_{ε}是主导 Z_{2}-even 标量 ε 的标度维度。
