Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: High Frequency dynamics in metallic glasses   Using Inelastic X-ray Scattering we studied the collective dynamics of the
glassy alloy Ni$_{33}$Zr$_{67}$ in the first pseudo Brillouin zone, an
energy-momentum region still unexplored in metallic glasses. We determine key
properties such as the momentum transfer dependence of the sound velocity and
of the acoustic damping, discussing the results in the general context of
recently proposed pictures for acoustic dynamics in glasses. Specifically, we
demonstrate the existence in this strong glass of well defined (in the Ioffe
Regel sense) acoustic-like excitations well above the Boson Peak energy.

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The categories of this paper are: nlin
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The categories of this paper are: hep-th
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The categories of this paper are: gr-qc
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The categories of this paper are: hep-ex
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The categories of this paper are: astro-ph
29
The categories of this paper are: funct-an
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The categories of this paper are: nucl-ex
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The categories of this paper are: dg-ga
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The categories of this paper are: acc-phys
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The categories of this paper are: solv-int
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The categories of this paper are: cs
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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: q-fin
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The categories of this paper are: alg-geom
30
The categories of this paper are: q-alg