Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Some Aspects of Optical Spatial Solitons in Photorefractive Crystals   We have reviewed recent developments of some aspects of optical spatial
solitons in photorefractive media. Underlying principles governing the dynamics
of photorefractive nonlinearity have been discussed using band transport model.
Nonlinear dynamical equations for propagating solitons have been derived
considering single as well as two-photon photorefractive processes. Fundamental
properties of three types of solitons, particularly, screening, photovoltaic
and screening photovoltaic solitons have been considered. For each type of
solitons, three different configurations i.e., bright, dark and gray varieties
have been considered. Mechanisms of formation of these solitons due to single
as well as two-photon photorefractive processes have been considered and their
self bending discussed. Vector solitons, particularly, incoherently coupled
solitons due to single photon and two-photon photorefractive phenomena have
been highlighted. Existence of some missing solitons have been also pointed
out.

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The categories of this paper are: hep-ex
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The categories of this paper are: mtrl-th
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The categories of this paper are: q-fin
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The categories of this paper are: acc-phys
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The categories of this paper are: hep-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: solv-int
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The categories of this paper are: chem-ph
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The categories of this paper are: econ
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The categories of this paper are: hep-lat
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The categories of this paper are: astro-ph
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The categories of this paper are: funct-an
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The categories of this paper are: q-alg
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The categories of this paper are: bayes-an
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The categories of this paper are: dg-ga
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The categories of this paper are: math-ph