Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Exact Static Axially Symmetric Thin Annular Dust Disks   A new family of exact solutions of the Einstein field equations for static
and axially simmetric spacetimes is presented. All the metric functions of the
solutions are explicitly computed and the obtained expressions are simply
written in terms of oblate spheroidal coordinates. The solutions describe an
infinite family of static axially symmetric thin annular dust disks. The disk
are of infinite extension but with an inner annular edge. The energy densities
of the disks are everywhere positive functions of the radial coordinate, equals
to zero at the inner edge of the disk, having a maximun at a finite value of
the radius and then vanishing at infinity. The disks have finite mass and their
energy-momentum tensor agrees with all the energy conditions.

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The categories of this paper are: patt-sol
9
The categories of this paper are: nlin
21
The categories of this paper are: adap-org
35
The categories of this paper are: mtrl-th
11
The categories of this paper are: hep-lat
20
The categories of this paper are: acc-phys
27
The categories of this paper are: comp-gas
14
The categories of this paper are: math-ph
13
The categories of this paper are: quant-ph
31
The categories of this paper are: ao-sci
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The categories of this paper are: alg-geom
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The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
0
The categories of this paper are: hep-ph
6
The categories of this paper are: astro-ph
17
The categories of this paper are: q-fin