Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Observatory for Multi-Epoch Gravitational Lens Astrophysics (OMEGA)   (abridged) The Observatory for Multi-Epoch Gravitational Lens Astrophysics
(OMEGA) is a mission concept for a 1.5-m near-UV through near-IR space
observatory that will be dedicated to frequent imaging and spectroscopic
monitoring of ~100 multiply-imaged active galactic nuclei over the whole sky.
Using wavelength-tailored dichroics with extremely high transmittance,
efficient imaging in six channels will be done simultaneously during each visit
to each target. The separate spectroscopic mode, engaged through a flip-in
mirror, uses an image slicer spectrograph. After a period of many visits to all
targets, the resulting multidimensional movies can then be analyzed to a)
measure the mass function of dark matter substructure; b) measure precise
masses of the accreting black holes as well as the structure of their accretion
disks and their environments over several decades of physical scale; and c)
measure a combination of the local Hubble expansion and cosmological distances
to unprecedented precision.

19
The categories of this paper are: eess
32
The categories of this paper are: atom-ph
13
The categories of this paper are: quant-ph
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The categories of this paper are: q-fin
14
The categories of this paper are: math-ph
18
The categories of this paper are: econ
1
The categories of this paper are: cs
25
The categories of this paper are: patt-sol
36
The categories of this paper are: cmp-lg
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The categories of this paper are: bayes-an
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The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
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The categories of this paper are: alg-geom
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The categories of this paper are: hep-th
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The categories of this paper are: chao-dyn
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The categories of this paper are: nucl-ex