Hierarchy of Fluctuation-Dissipation Theorems for the Classical   One-Component Plasma
  We have derived tractable cubic (p=3) and quartic (p=4) fluctuation-dissipation theorems (FDTs) for the classical one-component plasma in a form that links a single (p+1)-point dynamical structure function to a linear combination of pth-order density response functions amenable to calculation from model plasma kinetic equations. For p greater than or equal to 3, we note the emergence of "remainder" contributions comprised of clusters of lower-order dynamical structure functions which can be ultimately traded for response functions vis-a-vis the linear and quadratic FDTs. Our analysis paves the way for gaining a clear understanding of the structure of the FDT hierarchy. 
Kenneth Golden, Joshuah Heath
physics.plasm-ph