Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Representation Theorems for indefinite quadratic forms without spectral
  gap   The First and Second Representation Theorem for sign-indefinite quadratic
forms are extended. We include new cases of unbounded forms associated with
operators that do not necessarily have a spectral gap around zero. The kernel
of the associated operators is determined for special cases. This extends
results by Grubi\v{s}i\'c, Kostrykin, Makarov and Veseli\'c in [Mathematika 59
(2013), 169--189].

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The categories of this paper are: supr-con
7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
9
The categories of this paper are: nlin
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
4
The categories of this paper are: cond-mat
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: comp-gas
1
The categories of this paper are: cs
0
The categories of this paper are: hep-ph
14
The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph