Improved treatment of retarded self-energy calculations in perturbation theory

1996 ◽  
Vol 53 (16) ◽  
pp. 10569-10578 ◽  
Author(s):  
S. Wermbter
Keyword(s):  
Perturbation Theory ◽  
Energy Calculations ◽  
Self Energy

scholarly journals On the electrodynamic self-energy of the electron

1948 ◽  
Vol 195 (1041) ◽  
pp. 163-173
Keyword(s):  
Perturbation Theory ◽  
Wave Equation ◽  
Quantum Electrodynamics ◽  
Energy State ◽  
Energy Eigenvalue ◽  
Expansion Method ◽  
Negative Energy ◽  
The Self ◽  
Variation Principle ◽  
Self Energy

The stationary-state wave equation for an electron at rest in a negative-energy state in interaction with only its own electromagnetic field is considered. Quantum electrodynamics, single-electron theory and a ‘cut-off’ procedure in momentum-space are used. Expressions in the form of expansions in powers of e 2 /hc are derived for the wave function ψ and the energy-eigenvalue E by a method which (unlike perturbation theory) is not based on the assumption that the self-energy is small. The convergence of the expansion for E is not proved rigorously but the first few terms are shown to decrease rapidly. For low cut-off frequencies K 0 the expression for E behaves as the equivalent perturbation expression but for large K 0 it behaves as — J(e 2 /hc) hK0. The variation principle is applied to an approximation (obtained from the expansion method) for r/r, and it is proved rigorously that for large K 0 the self-energy is algebraically less than or equal to —J(e 2 /hc) hK 0 . Hence, if the electron wave-equation is considered as the limiting case of the ‘cut-off’ equation as K 0 ->ao, it is established that the divergences obtained are not merely due to improper use of perturbation theory and that the self-energy is indeed infinite.

Model dielectric matrices for quasiparticle self-energy calculations

1988 ◽  
Vol 37 (5) ◽  
pp. 2733-2736 ◽  
Author(s):  
Mark S. Hybertsen ◽  
Steven G. Louie
Keyword(s):  
Energy Calculations ◽  
Self Energy

First-principles self-energy calculations of carrier-induced band-gap narrowing in silicon

1992 ◽  
Vol 45 (23) ◽  
pp. 13741-13744 ◽  
Author(s):  
A. Oschlies ◽  
R. W. Godby ◽  
R. J. Needs
Keyword(s):  
Band Gap ◽  
First Principles ◽  
Energy Calculations ◽  
Self Energy ◽  
Band Gap Narrowing

A new Approach to the Electron Self-Energy Calculations

1999 ◽  
Vol T80 (B) ◽  
pp. 498
Author(s):  
A. V. Nefiodov ◽  
L. N. Labzowsky ◽  
I. A. Goidenko
Keyword(s):  
New Approach ◽  
Energy Calculations ◽  
Self Energy
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