Self-consistent Green's functions formalism with three-body interactions
Self-consistent Green's functions formalism with three-body interactions
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DOI：
10.1103/physrevc.88.054326
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发表时间：
2013-11-27
影响因子：
3.1
通讯作者：
Polls, Artur
中科院分区：
文献类型：
--
作者：
Carbone, Arianna;Cipollone, Andrea;Polls, Artur
我们扩展了自洽格林函数的形式，使其考虑到三体相互作用。我们根据费曼图分析了微扰展开，并定义了有效的一体和二体相互作用，这使得图的数量大大减少。这个过程可以看作是哈密顿量的正规排序到完全相关密度矩阵的推广。在微扰理论中给出了三阶的例子。为了定义非微扰近似，我们扩展了存在三体相互作用的运动方程方法。我们提出了可以提供三体相互作用的非摄动恢复的方案。我们还讨论了计算多体系统基态的科尔顿和规则的两种不同的扩展。
We extend the self-consistent Green's functions formalism to take into account three-body interactions. We analyze the perturbative expansion in terms of Feynman diagrams and define effective one- and two-body interactions, which allows for a substantial reduction of the number of diagrams. The procedure can be taken as a generalization of the normal ordering of the Hamiltonian to fully correlated density matrices. We give examples up to third order in perturbation theory. To define nonperturbative approximations, we extend the equation-of-motion method in the presence of three-body interactions. We propose schemes that can provide nonperturbative resummation of three-body interactions. We also discuss two different extensions of the Koltun sum rule to compute the ground state of a many-body system.