Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantization of Gravity in the Black Hole Background   We perform a covariant (Lagrangian) quantization of perturbative gravity in
the background of a Schwarzschild black hole. The key tool is a decomposition
of the field into spherical harmonics. We fix Regge-Wheeler gauge for modes
with angular momentum quantum number $l \geq 2$, while for low multipole modes
with $l$ $=$ $0$ or $1$ -- for which Regge-Wheeler gauge is inapplicable -- we
propose a set of gauge fixing conditions which are 2D background covariant and
perturbatively well-defined. We find that the corresponding Faddeev-Popov
ghosts are non-propagating for the $l\geq2$ modes, but are in general
nontrivial for the low multipole modes with $l = 0,1$. However, in
Schwarzschild coordinates, all time derivatives acting on the ghosts drop from
the action and the low multipole ghosts have instantaneous propagators. Up to
possible subtleties related to quantizing gravity in a space with a horizon,
Faddeev's theorem suggests the possibility of an underlying canonical
(Hamiltonian) quantization with a manifestly ghost-free Hilbert space.

12
The categories of this paper are: nucl-th
17
The categories of this paper are: q-fin
0
The categories of this paper are: hep-ph
26
The categories of this paper are: bayes-an
27
The categories of this paper are: comp-gas
25
The categories of this paper are: patt-sol
10
The categories of this paper are: q-bio
15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
21
The categories of this paper are: adap-org
13
The categories of this paper are: quant-ph
30
The categories of this paper are: q-alg
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
19
The categories of this paper are: eess
4
The categories of this paper are: cond-mat