Title of Paper:Four-point vertices from the 2PI and 4PI effective actions

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Date of Publication:2014-01-21

Journal:Phys.Rev. D

Discipline:Natural Science

First-Level Discipline:Physics

Volume:89

Issue:2

Page Number:025013

Abstract:We consider a symmetric scalar theory with quartic coupling in 2- and 3-dimensions and compare the self-consistent 4-point vertex obtained from the 4PI effective action with the Bethe-Salpeter 4-vertex from 2PI effective action. At zero external momenta the two vertices agree well with each other when the coupling strength is small, but differences between them become more and more pronounced as the coupling strength is increased. We also study the momentum dependence of the two vertices and show that for certain momentum configurations they are almost identical, but differ for general momentu

Note:arXiv:1310.4352，论文作者按姓氏排序，*为通讯作者