Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Symmetrized DMRG Method for Excited States of Hubbard Models   We extend the density matrix renormalization group method to exploit Parity,
$C_2$ (rotation by $\pi$) and electron-hole symmtries of model Hamiltonians. We
demonstrate the power of this method by obtaining the lowest energy states in
all the eight symmetry subspaces of Hubbard chains with upto 50 sites. The
ground-state energy, optical gap and spin gap of regular $U=4t$ and $U=6t$
Hubbard chains agree very well with exact results. This development extends the
scope of the DMRG method and allows future applications to study of optical
properties of low-dimensional conjugated polymeric systems.

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The categories of this paper are: comp-gas
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The categories of this paper are: hep-th
3
The categories of this paper are: physics
10
The categories of this paper are: q-bio
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The categories of this paper are: alg-geom
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The categories of this paper are: cmp-lg
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The categories of this paper are: q-fin
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The categories of this paper are: bayes-an
8
The categories of this paper are: hep-ex
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The categories of this paper are: econ
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The categories of this paper are: funct-an
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The categories of this paper are: ao-sci
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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: mtrl-th
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The categories of this paper are: chem-ph