Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A stable vacuum of the tachyonic E8 string   We consider tachyon condensation in unstable ten-dimensional heterotic string
theory with gauge group E8. In the background of a lightlike linear dilaton
rolling to weak coupling, we find an exact solution in which the theory decays
to a stable ground state. The final state represents a new, modular-invariant
perturbative string theory, tachyon-free in nine spacetime dimensions with a
spacelike dilaton gradient, E8 gauge group and no spacetime supersymmetry.

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The categories of this paper are: physics
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The categories of this paper are: gr-qc
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The categories of this paper are: alg-geom
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The categories of this paper are: q-bio
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The categories of this paper are: ao-sci
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The categories of this paper are: hep-ph
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The categories of this paper are: econ
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The categories of this paper are: nucl-th
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The categories of this paper are: mtrl-th
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The categories of this paper are: cmp-lg
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The categories of this paper are: bayes-an
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The categories of this paper are: math-ph
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The categories of this paper are: stat
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The categories of this paper are: cond-mat
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The categories of this paper are: comp-gas
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The categories of this paper are: eess