Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Comparison of different approaches of finding the positive definite
  metric in pseudo-Hermitian theories   To develop a unitary quantum theory with probabilistic description for
pseudo- Hermitian systems one needs to consider the theories in a different
Hilbert space endowed with a positive definite metric operator. There are
different approaches to find such metric operators. We compare the different
approaches of calculating pos- itive definite metric operators in
pseudo-Hermitian theories with the help of several explicit examples in
non-relativistic as well as in relativistic situations. Exceptional points and
spontaneous symmetry breaking are also discussed in these models.

16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
14
The categories of this paper are: math-ph
21
The categories of this paper are: adap-org
33
The categories of this paper are: plasm-ph
29
The categories of this paper are: funct-an
36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int
25
The categories of this paper are: patt-sol
34
The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
8
The categories of this paper are: hep-ex
37
The categories of this paper are: supr-con