Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Soft-Wall Stabilization   We propose a general class of five-dimensional soft-wall models with AdS
metric near the ultraviolet brane and four-dimensional Poincar\'e invariance,
where the infrared scale is determined dynamically. A large UV/IR hierarchy can
be generated without any fine-tuning, thus solving the electroweak/Planck scale
hierarchy problem. Generically, the spectrum of fluctuations is discrete with a
level spacing (mass gap) provided by the inverse length of the wall, similar to
RS1 models with Standard Model fields propagating in the bulk. Moreover two
particularly interesting cases arise. They can describe: (a) a theory with a
continuous spectrum above the mass gap which can model unparticles
corresponding to operators of a CFT where the conformal symmetry is broken by a
mass gap, and; (b) a theory with a discrete spectrum provided by linear Regge
trajectories as in AdS/QCD models.

9
The categories of this paper are: nlin
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The categories of this paper are: cmp-lg
11
The categories of this paper are: hep-lat
19
The categories of this paper are: eess
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The categories of this paper are: comp-gas
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The categories of this paper are: acc-phys
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The categories of this paper are: dg-ga
31
The categories of this paper are: ao-sci
2
The categories of this paper are: math
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The categories of this paper are: mtrl-th
34
The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
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The categories of this paper are: stat
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The categories of this paper are: quant-ph
32
The categories of this paper are: atom-ph