Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Density functional formulation of the Random Phase Approximation for
  inhomogeneous fluids: application to the Gaussian core and Coulomb particles   Using the adiabatic connection, we formulate the free energy in terms of the
correlation function of a fictitious system, $h_{\lambda}({\bf r},{\bf r}')$,
where $\lambda$ determines the interaction strength. To obtain
$h_{\lambda}({\bf r},{\bf r}')$ we use the Ornstein-Zernike equation, and the
two equations constitute a general liquid-state framework for treating
inhomogeneous fluids. As the two equations do not form a closed set, an
approximate closure relation is required and it determines a type of an
approximation. In the present work we investigate the random phase
approximation (RPA) closure. We determine that this approximation is identical
to the variational Gaussian approximation derived within the framework of the
field-theory. We then apply our generalized RPA approximation to the Gaussian
core model and Coulomb charges.

1
The categories of this paper are: cs
8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol
22
The categories of this paper are: chao-dyn
17
The categories of this paper are: q-fin
15
The categories of this paper are: nucl-ex
33
The categories of this paper are: plasm-ph
26
The categories of this paper are: bayes-an
16
The categories of this paper are: stat
9
The categories of this paper are: nlin
21
The categories of this paper are: adap-org
3
The categories of this paper are: physics
37
The categories of this paper are: supr-con
5
The categories of this paper are: gr-qc