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**Renormalised perturbation theory of normal systems.** / Lambert, Colin; Hagston, W. E. .

Research output: Contribution to Journal/Magazine › Journal article › peer-review

Lambert, C & Hagston, WE 1981, 'Renormalised perturbation theory of normal systems', *Journal of Physics A: Mathematical and General *, vol. 14, no. 7, pp. 1533-1542. https://doi.org/10.1088/0305-4470/14/7/010

Lambert, C., & Hagston, W. E. (1981). Renormalised perturbation theory of normal systems. *Journal of Physics A: Mathematical and General *, *14*(7), 1533-1542. https://doi.org/10.1088/0305-4470/14/7/010

Lambert C, Hagston WE. Renormalised perturbation theory of normal systems. Journal of Physics A: Mathematical and General . 1981 Jul;14(7):1533-1542. doi: 10.1088/0305-4470/14/7/010

@article{6e65ceb460724fb0b81460d10d94ca98,

title = "Renormalised perturbation theory of normal systems",

abstract = "Employing an infinite hierarchy of equations for the Green functions of a many particle system in its ground state mod psi N), the well known non-relativistic, time-dependent, ground-state perturbation theory of a normal system of interacting fermions is derived, without introducing the hypothesis that mod psi N) is the adiabatic transform of a non-interacting state. This new formulation of the problem allows us to renormalise conventional perturbation theory by introducing an effective interaction Gamma and the final result is a highly summed and manifestly self-consistent perturbation expansion in powers of Gamma . The authors calculate Gamma to second order and demonstrate that many of the well known results of time-dependent perturbation theory may be obtained by choosing the simplest approximations for Gamma . The results are readily generalised to finite temperatures and the formalism provides a generalised form of Hartree-Fock theory which may have important applications in many areas of physics.",

author = "Colin Lambert and Hagston, {W. E.}",

year = "1981",

month = jul,

doi = "10.1088/0305-4470/14/7/010",

language = "English",

volume = "14",

pages = "1533--1542",

journal = "Journal of Physics A: Mathematical and General ",

issn = "0305-4470",

publisher = "IOP Publishing Ltd",

number = "7",

}

TY - JOUR

T1 - Renormalised perturbation theory of normal systems

AU - Lambert, Colin

AU - Hagston, W. E.

PY - 1981/7

Y1 - 1981/7

N2 - Employing an infinite hierarchy of equations for the Green functions of a many particle system in its ground state mod psi N), the well known non-relativistic, time-dependent, ground-state perturbation theory of a normal system of interacting fermions is derived, without introducing the hypothesis that mod psi N) is the adiabatic transform of a non-interacting state. This new formulation of the problem allows us to renormalise conventional perturbation theory by introducing an effective interaction Gamma and the final result is a highly summed and manifestly self-consistent perturbation expansion in powers of Gamma . The authors calculate Gamma to second order and demonstrate that many of the well known results of time-dependent perturbation theory may be obtained by choosing the simplest approximations for Gamma . The results are readily generalised to finite temperatures and the formalism provides a generalised form of Hartree-Fock theory which may have important applications in many areas of physics.

AB - Employing an infinite hierarchy of equations for the Green functions of a many particle system in its ground state mod psi N), the well known non-relativistic, time-dependent, ground-state perturbation theory of a normal system of interacting fermions is derived, without introducing the hypothesis that mod psi N) is the adiabatic transform of a non-interacting state. This new formulation of the problem allows us to renormalise conventional perturbation theory by introducing an effective interaction Gamma and the final result is a highly summed and manifestly self-consistent perturbation expansion in powers of Gamma . The authors calculate Gamma to second order and demonstrate that many of the well known results of time-dependent perturbation theory may be obtained by choosing the simplest approximations for Gamma . The results are readily generalised to finite temperatures and the formalism provides a generalised form of Hartree-Fock theory which may have important applications in many areas of physics.

U2 - 10.1088/0305-4470/14/7/010

DO - 10.1088/0305-4470/14/7/010

M3 - Journal article

VL - 14

SP - 1533

EP - 1542

JO - Journal of Physics A: Mathematical and General

JF - Journal of Physics A: Mathematical and General

SN - 0305-4470

IS - 7

ER -