Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Universal Solutions in Open String Field Theory   An outstanding problem in open bosonic string field theory is the existence
of nontrivial classical solutions in its universal sector. Such solutions
independent of the underlying CFT would be relevant for any background, but
aside of the celebrated tachyon vacuum, no well behaved solutions have been
found so far. In this work we revisit the problem using the old fashioned level
truncation technique, but armed with much more sophisticated techniques and
greater computer power. In particular, using the homotopy continuation method
we construct all solutions at level 6 (or 5) with twist symmetry imposed (or
not), and improve the viable ones by Newton's method to levels 24-30.
Surprisingly, a handful of solutions survive. One of them is tantalizingly
close to the elusive double brane solution, although the fits to infinite level
seem to invalidate this conclusion. A better behaved solution matches
unexpectedly the properties of a ghost brane. This does not contradict
anything, since the solution violates the reality condition of string field
theory. Relaxing SU(1,1) singlet condition two more exotic solutions with the
rough characteristics of half brane and ghost half brane are found. For the
tachyon vacuum, by explicit numerical computations up to level 30, we confirm
the Gaiotto and Rastelli's prediction about the turning point of the tachyon
potential minimum as a function of the level.

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The categories of this paper are: dg-ga
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The categories of this paper are: atom-ph
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The categories of this paper are: q-bio
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The categories of this paper are: cond-mat
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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: math
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The categories of this paper are: adap-org
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The categories of this paper are: astro-ph
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The categories of this paper are: hep-ph
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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: q-alg
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The categories of this paper are: nlin
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The categories of this paper are: alg-geom
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The categories of this paper are: supr-con