Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum gravity corrections to the matter dynamics in the presence of a
  reference fluid   We analyze the effect induced on standard quantum field theory (in functional
approach) by quantum gravity corrections to a pure classical background. In the
framework of the Kucha\v{r} and Torre proposal for a gravity-matter theory
constrained to a Gaussian reference frame, materialized as a fluid in the
system evolution, we consider a Born-Oppenheimer separation of the system,
regarding the gravity degrees of freedom as the slow varying component and the
matter plus the Gaussian fluid as fast quantum coordinates. The slow gravity
component obeys the Wheeler-DeWitt equation and we consider a
Wentzel-Kramer-Brillouin expansion of its quantum dynamics via a Planckian
parameter. The main issue of the proposed scenario is that, on one hand, we
recover a modified quantum field theory in the presence of an Hermitian
Hamiltonian (not affected by non-unitarity as in other approaches) and, on the
other hand, we get the Gaussian fluid as a physical clock for such amended
quantum theory (verifying the correct energy conditions). We also show its
equivalence with the kinematical action method, used in a previous work, in the
homogeneous setting. Then, we implement the proposed paradigm to describe the
dynamics of a homogeneous free massless scalar field, living on an isotropic
Universe, in the presence of a cosmological constant. We completely solve the
dynamics up to the first order correction in the Planckian parameter to the
standard quantum field theory. We determine the explicit form of the modified
scalar field wave-function, due to quantum features of the cosmic scale factor
evolution. Phenomenological considerations and discussions are provided.

9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
30
The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
22
The categories of this paper are: chao-dyn
3
The categories of this paper are: physics
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
14
The categories of this paper are: math-ph
21
The categories of this paper are: adap-org
28
The categories of this paper are: alg-geom
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas