Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quasinormal ringing of general spherically symmetric parametrized black
  holes   The general parametrization of spherically symmetric and asymptotically flat
black-hole spacetimes in arbitrary metric theories of gravity was suggested in
[3]. The parametrization is based on the continued fraction expansion in terms
of the compact radial coordinate, has superior convergence and strict hierarchy
of parameters. It is known that some observable quantities, related to particle
motion around the black hole, such as the eikonal quasinormal modes, radius of
the shadow, frequency at the innermost stable circular orbit and others, depend
mostly on only a few lowest coefficients of the parametrization. Here we
continue this approach by studying the dominant (low-lying) quasinormal modes
for such generally parametrized black holes. We show that, due to the hierarchy
of parameters, the dominant quasinormal frequencies are also well determined by
only the first few coefficients of the expansion for the so called moderate
black-hole geometries. The latter are characterized by relatively slow change
of the metric functions in the radiation zone near the black hole. The
non-moderate metrics, which change strongly between the event horizon and the
innermost stable circular orbit are usually characterized by echoes or by too
distinctive (from the Einstein case) quasinormal ringing which does not match
the current observational data. Therefore, the compact description of a
black-hole spacetime in terms of the truncated general parametrization is an
effective formalism for testing strong gravity and imposing constrains on
allowed black-hole geometries.

25
The categories of this paper are: patt-sol
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
11
The categories of this paper are: hep-lat
16
The categories of this paper are: stat
37
The categories of this paper are: supr-con
20
The categories of this paper are: acc-phys
33
The categories of this paper are: plasm-ph
1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio
19
The categories of this paper are: eess
2
The categories of this paper are: math
9
The categories of this paper are: nlin
27
The categories of this paper are: comp-gas