Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Neither Name, Nor Number   Since its origins, Quantum mechanics has presented problems with the concept
of individuality. It is argued that quantum particles do not have
individuality, and so, one can speak about "entities without identity". On the
contrary, we claim that the problem of quantum non individuality goes deeper,
and that one of its most important features is the fact that there are quantum
systems for which particle number is not well defined. In this work, we
continue this discussion in relation to the problem about the one and the many.

9
The categories of this paper are: nlin
35
The categories of this paper are: mtrl-th
32
The categories of this paper are: atom-ph
23
The categories of this paper are: solv-int
1
The categories of this paper are: cs
27
The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph
8
The categories of this paper are: hep-ex
19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
3
The categories of this paper are: physics
17
The categories of this paper are: q-fin
36
The categories of this paper are: cmp-lg
34
The categories of this paper are: chem-ph