Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Phonon Anomalies Induced by Superconductivity   We calculate the electronic polarizability in the superconducting state near
extremum vectors ${\vec Q}_0$ of the Fermi surface. A pole appears in the
polarizability at frequencies $\omega$ near the superconducting gap $2\Delta$
which leads to a sharp peak at $\omega$ just below $2 \Delta$ in the lattice
vibrations near ${\vec Q}_0$. A second order transition to a charge density
wave state below the superconducting transition is shown to be unlikely. The
results are compared with the recent inelastic neutron scattering measurements
in compounds, $ANi_2B_2C$, $A=Y$ or $Lu$.

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The categories of this paper are: hep-lat
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The categories of this paper are: acc-phys
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The categories of this paper are: adap-org
36
The categories of this paper are: cmp-lg
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The categories of this paper are: quant-ph
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The categories of this paper are: q-fin
0
The categories of this paper are: hep-ph
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The categories of this paper are: funct-an
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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: solv-int
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The categories of this paper are: atom-ph
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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: q-bio
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The categories of this paper are: bayes-an