Real-time Kadanoff-Baym approach to nuclear response functions

H. S. Köhler, Nai-Hang Kwong

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Linear density response functions are calculated for symmetric nuclear matter of normal density by time-evolving two-time Green's functions in real time. Of particular interest is the effect of correlations. The system is therefore initially time-evolved with a collision term calculated in a direct Born approximation until fully correlated. An external time-dependent potential is then applied. The ensuing density fluctuations are recorded to calculate the density response. This method was previously used by Kwong and Bonitz for studying plasma oscillations in a correlated electron gas. The energy-weighted sum-rule for the response function is guaranteed by using conserving self-energy insertions as the method then generates the full vertex-functions. These can alternatively be calculated by solving a Bethe -Salpeter equation as done in works by Bozek et al. The (first order) mean field is derived from a momentum-dependent (non-local) interaction while 2nd order self-energies are calculated using a particle-hole two-body effective (or residual) interaction given by a gaussian local potential. We show results of calculations of the response function S(,q0 ) for q0 = 0.2, 0.4 and 0.8fm -1. Comparison is made with the nucleons being un-correlated i.e. with only the first order mean field included. We discuss the relation of our work with the Landau quasi-particle theory as applied to nuclear systems by Babu and Brown and followers.

Original languageEnglish (US)
Article number012011
JournalJournal of Physics: Conference Series
Volume696
Issue number1
DOIs
StatePublished - Apr 12 2016

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particle theory
Bethe-Salpeter equation
time functions
plasma oscillations
elementary excitations
Born approximation
nucleons
sum rules
electron gas
energy
insertion
apexes
Green's functions
interactions
momentum
collisions

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Real-time Kadanoff-Baym approach to nuclear response functions. / Köhler, H. S.; Kwong, Nai-Hang.

In: Journal of Physics: Conference Series, Vol. 696, No. 1, 012011, 12.04.2016.

Research output: Contribution to journalArticle

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