Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Gravitational wave experiments and Baksan project "OGRAN"   A brief sketch of the present status of gravitational wave experiments is
given. Attention is concentrated to recent observations with the gravitational
detector network. The project OGRAN for a combined optic-interferometrical and
acoustical gravitation wave antenna planned for installation into underground
facilities of the Baksan Neutrino Observatory is presented. We describe general
principles of the apparatus, expected sensitivity and current characteristics
of the antenna prototype; some ways for sensitivity improvement are also
discussed.

24
The categories of this paper are: dg-ga
22
The categories of this paper are: chao-dyn
36
The categories of this paper are: cmp-lg
19
The categories of this paper are: eess
25
The categories of this paper are: patt-sol
11
The categories of this paper are: hep-lat
29
The categories of this paper are: funct-an
33
The categories of this paper are: plasm-ph
4
The categories of this paper are: cond-mat
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The categories of this paper are: alg-geom
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The categories of this paper are: q-fin
34
The categories of this paper are: chem-ph
27
The categories of this paper are: comp-gas
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The categories of this paper are: solv-int
0
The categories of this paper are: hep-ph
12
The categories of this paper are: nucl-th