Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: General parametrization of axisymmetric black holes in metric theories
  of gravity   Following previous work of ours in spherical symmetry, we here propose a new
parametric framework to describe the spacetime of axisymmetric black holes in
generic metric theories of gravity. In this case, the metric components are
functions of both the radial and the polar angular coordinates, forcing a
double expansion to obtain a generic axisymmetric metric expression. In
particular, we use a continued-fraction expansion in terms of a compactified
radial coordinate to express the radial dependence, while we exploit a Taylor
expansion in terms of the cosine of the polar angle for the polar dependence.
These choices lead to a superior convergence in the radial direction and to an
exact limit on the equatorial plane. As a validation of our approach, we build
parametrized representations of Kerr, rotating dilaton, and
Einstein-dilaton-Gauss-Bonnet black holes. The match is already very good at
lowest order in the expansion and improves as new orders are added. We expect a
similar behavior for any stationary and axisymmetric black-hole metric.

31
The categories of this paper are: ao-sci
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The categories of this paper are: dg-ga
28
The categories of this paper are: alg-geom
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The categories of this paper are: eess
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The categories of this paper are: q-fin
13
The categories of this paper are: quant-ph
33
The categories of this paper are: plasm-ph
16
The categories of this paper are: stat
15
The categories of this paper are: nucl-ex
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The categories of this paper are: comp-gas
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The categories of this paper are: mtrl-th
20
The categories of this paper are: acc-phys
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The categories of this paper are: supr-con
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The categories of this paper are: econ
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an