Linked-cluster perturbative expansion in correlated-basis theory

Mar 1, 1984
6 pages
Published in:
  • Phys.Rev.B 29 (1984) 2544-2550

Citations per year

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Abstract: (APS)
We give a brief outline of the perturbative expansion and the cluster properties of nondiagonal matrix elements in correlated-basis theory. A structural study of the perturbative series shows the presence of systematic cancellations among the terms of the series. It is proved by virtue of these cancellations that the expansion is linked and closely resembles the perturbative expansion of Brueckner-Goldstone theory. It is found that the ladder diagrams can be summed up by solving a Bethe-Goldstone—type equation which has recently been derived in correlated coupled-cluster theory. A brief discussion of some properties of ring diagrams is also given.