Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Hidden Symmetries in Second Class Constrained Systems - Are New Fields
  Necessary?   For many systems with second class constraints, the question posed in the
title is answered in the negative. We prove this for a range of systems with
two second class constraints. After looking at two examples, we consider a
fairly general proof. It is shown that, to unravel gauge invariances in second
class constrained systems, it is sufficient to work in the original phase space
itself. Extension of the phase space by introducing new variables or fields is
not required.

20
The categories of this paper are: acc-phys
8
The categories of this paper are: hep-ex
17
The categories of this paper are: q-fin
6
The categories of this paper are: astro-ph
5
The categories of this paper are: gr-qc
16
The categories of this paper are: stat
2
The categories of this paper are: math
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio
24
The categories of this paper are: dg-ga
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The categories of this paper are: bayes-an
23
The categories of this paper are: solv-int