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Title: Cumulant expansion of the retarded one-electron Green function

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Journal Article: Publisher's Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 90; Journal Issue: 8; Journal ID: ISSN 1098-0121
American Physical Society
Country of Publication:
United States

Citation Formats

Kas, J. J., Rehr, J. J., and Reining, L.. Cumulant expansion of the retarded one-electron Green function. United States: N. p., 2014. Web. doi:10.1103/PhysRevB.90.085112.
Kas, J. J., Rehr, J. J., & Reining, L.. Cumulant expansion of the retarded one-electron Green function. United States. doi:10.1103/PhysRevB.90.085112.
Kas, J. J., Rehr, J. J., and Reining, L.. Mon . "Cumulant expansion of the retarded one-electron Green function". United States. doi:10.1103/PhysRevB.90.085112.
title = {Cumulant expansion of the retarded one-electron Green function},
author = {Kas, J. J. and Rehr, J. J. and Reining, L.},
abstractNote = {},
doi = {10.1103/PhysRevB.90.085112},
journal = {Physical Review B},
number = 8,
volume = 90,
place = {United States},
year = {Mon Aug 11 00:00:00 EDT 2014},
month = {Mon Aug 11 00:00:00 EDT 2014}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1103/PhysRevB.90.085112

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Cited by: 23works
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  • Cited by 3
  • A cumulant-based GW approximation for the retarded one-particle Green's function is proposed, motivated by an exact relation between the improper Dyson self-energy and the cumulant generating function. We explore qualitative aspects of this method within a simple one-electron independent phonon model, where it is seen that the method preserves the energy moment of the spectral weight while also reproducing the exact Green's function in the weak-coupling limit. For the three-dimensional electron gas, this method predicts multiple satellites at the bottom of the band, albeit with inaccurate peak spacing. But, its quasiparticle properties and correlation energies are more accurate than bothmore » previous cumulant methods and standard G0W0. These results point to features that may be exploited within the framework of cumulant-based methods and suggest promising directions for future exploration and improvements of cumulant-based GW approaches.« less
  • The structure function {ital S}({ital q},{omega}) for quasielastic electron scattering on a nonrelativistic two-nucleon model system is evaluated numerically. These {ital S} values are considered as pseudodata to study sum rules, {ital y} scaling, and the cumulant expansion. For the force models considered it is found that the reduced structure function ({ital q}/2{ital m}){ital S}({ital q},{omega}) in the limit {ital q}{r arrow}{infinity} scales to the longitudinal momentum distribution {ital P}{sub {ital L}}({ital y}) in the target. Except for small {ital y} values, this limit, however, is reached only very slowly, which may be due to the strictly nonrelativistic treatment. Themore » cumulant expansion based on low-order cumulants is not useful. We also derive the analytical result that in our potential model {ital S}({ital q},{omega})={ital O}({omega}{sup {minus}5.5}) for {omega}{r arrow}{infinity} and fixed {ital q}. This shows that higher-order cumulants do not exist.« less
  • Cited by 10
  • The space-charge forces for short electron bunches in circular motion can be very different from the space-charge forces for short electron bunches undergoing straight-line motion. The two major effects introduced by the circular motion are an off-axis, so-called {open_quote}{open_quote}noninertial space-charge{close_quote}{close_quote} effect, in which there is essentially no net energy loss of the bunch, and a coherent synchrotron radiation effect, in which the bunch radiates coherent energy. The consequence of these effects is a potentially large growth in the electron bunch{close_quote}s transverse emittance. We derive an expression for these forces from a Green{close_quote}s function approach, starting with the definitions of themore » retarded scalar and vector potentials. In particular, we find an expression for the total electric field along the direction of motion from a short line of charge in circular motion. These expressions in turn can be used in numerical particle simulations to estimate the amount of emittance growth, including the effects of suppressing the coherent synchrotron radiation by reducing the beam pipe dimensions. {copyright} {ital 1996 The American Physical Society.}« less