Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Phonon spectral function for an interacting electron-phonon system   Using exact diagonalzation techniques, we study a model of interacting
electrons and phonons. The spectral width of the phonons is found to be reduced
as the Coulomb interaction U is increased. For a system with two modes per
site, we find a transfer of coupling strength from the upper to the lower mode.
This transfer is reduced as U is increased. These results give a qualitative
explanation of differences between Raman and photoemission estimates of the
electron-phonon coupling constants for A3C60 (A= K, Rb).

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The categories of this paper are: mtrl-th
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The categories of this paper are: dg-ga
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The categories of this paper are: patt-sol
18
The categories of this paper are: econ
11
The categories of this paper are: hep-lat
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The categories of this paper are: cmp-lg
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The categories of this paper are: adap-org
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The categories of this paper are: acc-phys
13
The categories of this paper are: quant-ph
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The categories of this paper are: nlin
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The categories of this paper are: chao-dyn
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The categories of this paper are: supr-con
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The categories of this paper are: math
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The categories of this paper are: gr-qc
3
The categories of this paper are: physics
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The categories of this paper are: nucl-ex