The exact solution of the many-body problem in one-point: insights in approximate Green's function approaches

ORAL

Abstract

In this work we obtain the exact one-body Green's function in one point by solving the Kadanoff-Baym equation. The result is a family of solutions. We show that only one of these solutions is a physical solution. We compare the exact physical solution to the exact solution of an approximate Kadanoff-Baym equation that was obtained recently [1] as well as to standard approximations such as GW. We show that the iterative solution of the GW equations is not always equal to the exact GW result. \\[4pt] [1] G. Lani, P. Romaniello and L. Reining, New J. Phys. 14, 013056 (2012)

–

Authors

  • Arjan Berger

    • Laboratoire de Chimie et Physique Quantiques (IRSAMC), UPS, CNRS, Toulouse, France and European Theoretical Spectroscopy Facility (ETSF)

  • Pina Romaniello

    • Laboratoire de Physique Th\'eorique (IRSAMC), CNRS, UPS, Toulouse, France and European Theoretical Spectroscopy Facility (ETSF)
    • LPT, CNRS, University P. Sabatier and ETSF

  • Lucia Reining

    • Laboratoire des Solides Irradi\'es, Ecole Polytechnique, Palaiseau, France and European Theoretical Spectroscopy Facility (ETSF)
    • LSI, Ecole Polytechnique, CNRS and ETSF