Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Density-functional theory for attraction between like-charged plates   We study the interactions between two negatively charged macroscopic surfaces
confining positive counterions. A density-functional approach is introduced
which, besides the usual mean-field interactions, takes into account the
correlations in the positions of counterions. The excess free energy is derived
in the framework of the Debye-H{\"u}ckel theory of the one-component plasma,
with the homogeneous density replaced by a weighted density. The minimization
of the total free energy yields the density profile of the microions. The
pressure is calculated and compared with the simulations and the results
derived from integral equations theories. We find that the interaction between
the two plates becomes attractive when their separation distance is
sufficiently small and the surface charge density is larger than a threshold
value.

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The categories of this paper are: hep-ph
2
The categories of this paper are: math
17
The categories of this paper are: q-fin
26
The categories of this paper are: bayes-an
27
The categories of this paper are: comp-gas
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
30
The categories of this paper are: q-alg
22
The categories of this paper are: chao-dyn
31
The categories of this paper are: ao-sci
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
15
The categories of this paper are: nucl-ex
6
The categories of this paper are: astro-ph
8
The categories of this paper are: hep-ex
20
The categories of this paper are: acc-phys