Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Density Matrix Renormalization Group Approach to the Massive Schwinger
  Model   The massive Schwinger model is studied, using a density matrix
renormalization group approach to the staggered lattice Hamiltonian version of
the model. Lattice sizes up to 256 sites are calculated, and the estimates in
the continuum limit are almost two orders of magnitude more accurate than
previous calculations. Coleman's picture of `half-asymptotic' particles at
background field (theta = pi) is confirmed. The predicted phase transition at
finite fermion mass (m/g) is accurately located, and demonstrated to belong in
the 2D Ising universality class.

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The categories of this paper are: ao-sci
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The categories of this paper are: adap-org
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The categories of this paper are: eess
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The categories of this paper are: nucl-th
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The categories of this paper are: supr-con
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The categories of this paper are: atom-ph
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The categories of this paper are: solv-int
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The categories of this paper are: hep-ph
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The categories of this paper are: quant-ph
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The categories of this paper are: q-bio
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The categories of this paper are: comp-gas
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The categories of this paper are: q-alg
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The categories of this paper are: cs
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The categories of this paper are: math-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: stat