Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: BRST Analysis of Physical Fields and States for 4D Quantum Gravity on R
  x S^3   We consider the background-free quantum gravity based on conformal gravity
with the Riegert-Wess-Zumino action, which is formulated in terms of a
conformal field theory. Employing the $R \times S^3$ background in practice, we
construct the nilpotent BRST operator imposing diffeomorphism invariance.
Physical fields and states are analyzed, which are given only by real primary
scalars with a definite conformal weight. With attention to the presence of
background charges, various significant properties, such as the state-operator
correspondence and the norm structure, are clarified with some examples.

21
The categories of this paper are: adap-org
24
The categories of this paper are: dg-ga
29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio
30
The categories of this paper are: q-alg
6
The categories of this paper are: astro-ph
34
The categories of this paper are: chem-ph
36
The categories of this paper are: cmp-lg
32
The categories of this paper are: atom-ph
25
The categories of this paper are: patt-sol
4
The categories of this paper are: cond-mat
3
The categories of this paper are: physics
1
The categories of this paper are: cs
27
The categories of this paper are: comp-gas
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys