Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A statistical physics of stationary and metastable states: description
  of the plasma column experimental data   We propose a statistical mechanics for a general class of stationary and
metastable equilibrium states. For this purpose, the Gibbs extremal conditions
are slightly modified in order to be applied to a wide class of non-equilibrium
states. As usual, it is assumed that the system maximizes the entropy
functional $S$, subjected to the standard conditions; i.e., constant energy and
normalization of the probability distribution. However, an extra conserved
constraint function $F$ is also assumed to exist, which forces the system to
remain in the metastable configuration. Further, after assuming additivity for
two quasi-independent subsystems, and that the new constraint commutes with
density matrix $\rho$, it is argued that F should be an homogeneous function of
the density matrix, at least for systems in which the spectrum is sufficiently
dense to be considered as continuous. The explicit form of $F$ turns to be
$F(p_{i})=p_{i}^{q}$, where $p_i$ are the eigenvalues of the density matrix and
$q$ is a real number to be determined. This $q$ number appears as a kind of
Tsallis parameter having the interpretation of the order of homogeneity of the
constraint $F$. The procedure is applied to describe the results of the plasma
experiment of Huang and Driscoll. The experimentally measured density is
predicted with a similar precision as it is done with the use of the extremum
of the enstrophy and Tsallis procedures. However, the present results define
the density at all the radial positions. In particular, the smooth tail shown
by the experimental distribution turns to be predicted by the procedure. In
this way, the scheme avoids the non-analyticity of the density profile at large
distances arising in both of the mentioned alternative procedures.

32
The categories of this paper are: atom-ph
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat
35
The categories of this paper are: mtrl-th
3
The categories of this paper are: physics
19
The categories of this paper are: eess
9
The categories of this paper are: nlin
22
The categories of this paper are: chao-dyn
2
The categories of this paper are: math
6
The categories of this paper are: astro-ph
28
The categories of this paper are: alg-geom
17
The categories of this paper are: q-fin
21
The categories of this paper are: adap-org
25
The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
31
The categories of this paper are: ao-sci