Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Omnidirectional Gravitational Wave Detector with a Laser-Interferometric
  Gravitational Compass   Based on the Szekeres-Pirani gravitational compass we suggest the addition of
a fourth, non-coplanar mass/mirror to the presently existing laser based
gravitational wave observatories, enabling them to operate omnidirectionally,
to filter out ambiguous interpretations and to point out the direction of the
gravitational wave source.

1
The categories of this paper are: cs
3
The categories of this paper are: physics
16
The categories of this paper are: stat
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
9
The categories of this paper are: nlin
12
The categories of this paper are: nucl-th
21
The categories of this paper are: adap-org
13
The categories of this paper are: quant-ph
34
The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg
0
The categories of this paper are: hep-ph
8
The categories of this paper are: hep-ex
7
The categories of this paper are: hep-th
26
The categories of this paper are: bayes-an
32
The categories of this paper are: atom-ph