论文标题
重新归一化的扰动理论用于快速评估真实频率轴上的Feynman图
Renormalized Perturbation Theory for Fast Evaluation of Feynman Diagrams on the Real Frequency Axis
论文作者
论文摘要
我们提出了一种在实际频率轴上表达时加速Feynman图的空间积分的数值评估的方法。这可以通过使用恒定但复杂的重新归一化转移的重新归一化扰动扩展来实现。复杂的偏移充当正规化参数，用于启动锋利函数的数值集成。这会导致随机数值集成的指数速度，但要评估其他违反期图。我们提供概念验证计算，以在正方形晶格上的半填充2D哈伯德模型的困难极限内。
We present a method to accelerate the numerical evaluation of spatial integrals of Feynman diagrams when expressed on the real frequency axis. This can be realized through use of a renormalized perturbation expansion with a constant but complex renormalization shift. The complex shift acts as a regularization parameter for the numerical integration of otherwise sharp functions. This results in an exponential speed up of stochastic numerical integration at the expense of evaluating additional counter-term diagrams. We provide proof of concept calculations within a difficult limit of the half-filled 2D Hubbard model on a square lattice.
