Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Can the conformal factor of the gravitational field be a physical degree
  of freedom?   The role of the conformal factor was analysed in two gauge-invariant
perturbative formulations. Using the classical and quantum linearized
perturbation approach given by Mukhanov et al \cite{Mukhanov:1990me}, the
non-physical behaviour of the conformal perturbation as an isolated degree of
freedom is shown. In the quantum gravity context, the restriction to conformal
perturbations gives us an incompatibility with the dynamical equations.

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The categories of this paper are: math-ph
25
The categories of this paper are: patt-sol
34
The categories of this paper are: chem-ph
24
The categories of this paper are: dg-ga
8
The categories of this paper are: hep-ex
10
The categories of this paper are: q-bio
15
The categories of this paper are: nucl-ex
33
The categories of this paper are: plasm-ph
26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
0
The categories of this paper are: hep-ph
1
The categories of this paper are: cs
13
The categories of this paper are: quant-ph
19
The categories of this paper are: eess
35
The categories of this paper are: mtrl-th
21
The categories of this paper are: adap-org