Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Elimination of cosmological singularities in quantum cosmology by
  suitable operator orderings   Canonical quantization of general relativity does not yield a unique quantum
theory for gravity. This is in part due to operator ordering ambiguities. In
this paper, we investigate the role of different operator orderings on the
question of whether a big bang or big crunch singularity occurs. We do this in
the context of the minisuperspace model of a
Friedmann-Lemaitre-Robertson-Walker universe with Brown-Kuchar dust. We find
that for a certain class of operator orderings such a singularity is eliminated
without having to impose boundary conditions.

34
The categories of this paper are: chem-ph
25
The categories of this paper are: patt-sol
24
The categories of this paper are: dg-ga
6
The categories of this paper are: astro-ph
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
22
The categories of this paper are: chao-dyn
8
The categories of this paper are: hep-ex
14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
4
The categories of this paper are: cond-mat
1
The categories of this paper are: cs
35
The categories of this paper are: mtrl-th
19
The categories of this paper are: eess
0
The categories of this paper are: hep-ph