Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Momentum distribution functions in ensembles: the inequivalence of
  microcannonical and canonical ensembles in a finite ultracold system   It is demonstrated that in many thermodynamic textbooks the equivalence of
the different ensembles is achieved in the thermodynamic limit. In this present
work we remark the inequivalence of microcannonical and canonical ensembles in
a finite ultracold system at low energies. We calculate the microcanonical
momentum distribution function (MDF) in a system of identical fermions
(bosons). We find that, the microcanonical MDF deviates from the canonical one,
which is the Fermi-Dirac (Bose-Einstein) function, in a finite system at low
energies where the single-particle density of states and its inverse are
finite.

18
The categories of this paper are: econ
3
The categories of this paper are: physics
13
The categories of this paper are: quant-ph
9
The categories of this paper are: nlin
25
The categories of this paper are: patt-sol
16
The categories of this paper are: stat
26
The categories of this paper are: bayes-an
15
The categories of this paper are: nucl-ex
27
The categories of this paper are: comp-gas
29
The categories of this paper are: funct-an
0
The categories of this paper are: hep-ph
31
The categories of this paper are: ao-sci
33
The categories of this paper are: plasm-ph
7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom