ISSN:
1572-9613
Keywords:
Response function
;
correlations
;
dynamical structure function
;
quadratic response function
;
fluctuation-dissipation theorem
;
plasma
;
electron gas
;
many-body systems
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract We analyze a new type of response function which portrays the properties of a system perturbed by an external field in terms of the perturbed two-point correlations of density fluctuations rather than in terms of perturbed averages of physical quantities. This “response function of the second kind” satisfies both fluctuation-dissipation-like theorems, relating it to three-point equilibrium functions, and hierarchical relationship linking it to conventional quadratic (rather than linear) response functions. In the equal-time limit, when the two density fluctuations are observed at the same time, the response function of the second kind is intimately connected to the two-particle correlation function of kinetic theory. This linkage opens an avenue for developing novel approximation techniques for correlated many-body systems.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01053598
Permalink
