Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The grand canonical catastrophe as an instance of condensation of
  fluctuations   The so-called grand canonical catastrophe of the density fluctuations in the
ideal Bose gas is shown to be a particular instance of the much more general
phenomenon of condensation of fluctuations, taking place in a large system, in
or out of equilibrium, when a single degree of freedom makes a macroscopic
contribution to the fluctuations of an extensive quantity. The pathological
character of the "catastrophe" is demystified by emphasizing the connection
between experimental conditions and statistical ensembles, as demonstrated by
the recent realization of photon condensation under grand canonical conditions.

35
The categories of this paper are: mtrl-th
6
The categories of this paper are: astro-ph
14
The categories of this paper are: math-ph
1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
16
The categories of this paper are: stat
32
The categories of this paper are: atom-ph
28
The categories of this paper are: alg-geom
24
The categories of this paper are: dg-ga
2
The categories of this paper are: math
3
The categories of this paper are: physics
27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio