Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Vavilov-Cerenkov phenomenon in metal nanofilms   The Vavilov-Cerenkov phenomenon - light emission during the motion of a fast
electron in a dense medium is observable in homogeneous media as well as in
inhomogeneous media like photonic crystals. So long as a space (homogeneous or
inhomogeneous) contains natural waves with phase velocities that are lower than
the velocity of a flying through electron then a Cerenkov emission of light
would appear. In nanofilms and nanowires made of silver, gold, copper there are
so called surface plasmon polaritons, namely natural waves with a low phase
velocity. These waves velocity could be by tens and hundreds times lower than
the light velocity in vacuum. An electron with a velocity that is comparatively
lower than a velocity of an electron that is able to emit in a uniform medium
could emit Cerenkov light. Dispersion relations are calculated for the
corresponding plasmons as well as the angles of emission of the plasmons of
corresponding frequencies.

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The categories of this paper are: cond-mat
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The categories of this paper are: solv-int
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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: supr-con
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The categories of this paper are: mtrl-th
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The categories of this paper are: chem-ph
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The categories of this paper are: eess
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The categories of this paper are: nucl-th
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The categories of this paper are: math
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The categories of this paper are: cs
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The categories of this paper are: quant-ph
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The categories of this paper are: q-alg
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The categories of this paper are: chao-dyn
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The categories of this paper are: funct-an
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The categories of this paper are: patt-sol