Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Infrared Conductivity of Cuprate Metals: Detailed Fit Using Luttinger
  Liquid Theory   Measurements of infrared conductivity in the normal state of the cuprate
layer metals show a characteristic behavior in the plane of the layers which is
in essential agreement among many experiments. A simple parametrization of this
behavior, proposed originally by Collins and Schlesinger, and exploited by N.
Bontemps and her group, which gives an adequate fit over frequencies from a few
hundred cm$^{-1}$ to $>5000 $ cm$^{-1}$, is that the phase angle of the complex
conductivity is independent of frequency. This fit is shown to be a natural
consequence of Luttinger Liquid theory with charge-spin separation, and
determines the exponent of the singularity at the Fermi surface to be $\sim
.15\pm .05$.

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The categories of this paper are: q-bio
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The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
25
The categories of this paper are: patt-sol
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The categories of this paper are: nlin
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The categories of this paper are: comp-gas
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The categories of this paper are: physics
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The categories of this paper are: hep-lat
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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: econ
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The categories of this paper are: plasm-ph
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The categories of this paper are: hep-th
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The categories of this paper are: alg-geom
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The categories of this paper are: nucl-th