论文标题
在大扩展顺序上重新归一化的扰动理论
Renormalized perturbation theory at large expansion orders
论文作者
论文摘要
我们提出了一种一般的形式主义，该形式允许在时空表示中计算大阶重新归一化的扩展，从而有效地将重新归一化的Feynman图的数值可达到的扰动顺序翻了一番。我们表明，由于其高效率，简单性和广泛的适用性，该公式与当前标准技术有利相比。我们的形式主义允许通过非扰动信息轻松地补充扰动理论，我们通过实施通过添加差距或包含动态平均场理论重新归一化的扩展来说明这一点。结果，我们介绍了低温非温度非弗米 - 液体方案中方晶格费米 - 哈伯德模型的数值限制结果，并显示了对抗焦点区域中费米的动量依赖性抑制。
We present a general formalism that allows for the computation of large-order renormalized expansions in the spacetime representation, effectively doubling the numerically attainable perturbation order of renormalized Feynman diagrams. We show that this formulation compares advantageously to the currently standard techniques due to its high efficiency, simplicity, and broad range of applicability. Our formalism permits to easily complement perturbation theory with non-perturbative information, which we illustrate by implementing expansions renormalized by the addition of a gap or the inclusion of Dynamical Mean-Field Theory. As a result, we present numerically-exact results for the square-lattice Fermi-Hubbard model in the low temperature non-Fermi-liquid regime and show the momentum-dependent suppression of fermionic excitations in the antinodal region.
