Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quadrupolar gravitational fields described by the $q-$metric   We investigate the Zipoy-Voorhees metric ($q-$metric) as the simplest static,
axially symmetric solution of Einstein's vacuum field equations that possesses
as independent parameters the mass and the quadrupole moment. In accordance
with the black holes uniqueness theorems, the presence of the quadrupole
completely changes the geometric properties of the corresponding spacetime that
turns out to contain naked singularities for all possible values of the
quadrupole parameter. The naked singularities, however, can be covered by
interior solutions that correspond to perfect fluid sources with no specific
equations of state. We conclude that the $q-$metric can be used to describe the
entire spacetime generated by static deformed compact objects.

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The categories of this paper are: hep-th
30
The categories of this paper are: q-alg
21
The categories of this paper are: adap-org
33
The categories of this paper are: plasm-ph
4
The categories of this paper are: cond-mat
23
The categories of this paper are: solv-int
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin
15
The categories of this paper are: nucl-ex
26
The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs
14
The categories of this paper are: math-ph
8
The categories of this paper are: hep-ex