Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: $T\bar T$, Black Holes and Negative Strings   String theory on $AdS_3$ has a solvable single-trace irrelevant deformation
that is closely related to $T\bar T$. For one sign of the coupling, it leads to
an asymptotically linear dilaton spacetime, and a corresponding Hagedorn
spectrum. For the other, the resulting spacetime has a curvature singularity at
a finite radial location, and an upper bound on the energies of states. Beyond
the singularity, the signature of spacetime is flipped and there is an
asymptotically linear dilaton boundary at infinity. We study the properties of
black holes and fundamental strings in this spacetime, and find a sensible
picture. The singularity does not give rise to a hard ultraviolet wall for
excitations -- one must include the region beyond it to understand the theory.
The size of black holes diverges as their energy approaches the upper bound, as
does the location of the singularity. Fundamental strings pass smoothly through
the singularity, but if their energy is above the upper bound, their
trajectories are singular. From the point of view of the boundary at infinity,
this background can be thought of as a vacuum of Little String Theory which
contains a large number of negative strings.

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The categories of this paper are: quant-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: alg-geom
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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: hep-ex
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The categories of this paper are: q-bio
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The categories of this paper are: atom-ph
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The categories of this paper are: q-alg
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The categories of this paper are: funct-an
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The categories of this paper are: comp-gas
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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: acc-phys
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The categories of this paper are: chem-ph
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The categories of this paper are: q-fin