Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Conformalons and Trans-Planckian problem   In any conformally invariant gravitational theory, the space of exact
solutions is greatly enlarged. The Weyl's conformal invariance can then be
spontaneously broken to spherically symmetric vacuum solutions that exclude the
spacetime region inside the black hole's event horizon from our Universe. We
baptize these solutions ''conformalons''. It turns out that for all such
spacetimes nothing can reach the Schwarzschild event horizon in a finite amount
of proper time for conformally coupled ``massive'' particles, or finite values
of the affine parameter for massless particles. Therefore, for such vacuum
solutions the event horizon is an asymptotic region of the Universe. As a
general feature, all conformalons show a gravitational blueshift instead of a
gravitational redshift at the unattainable event horizon, hence avoiding the
Trans-Planckian problem in the Hawking evaporation process. The latter happens
as usual near the event horizon, but now the annihilation process between the
matter and Hawking's negative energy particles takes place outside of the event
horizon. Indeed, in these solutions the gravitational collapse consists of
matter that falls down forever towards the horizon without ever reaching it.
According to a previous work that has been faithfully adapted to the
conformalons' scenario, the information is not lost in the whole process of
singularity-free collapse and evaporation, as evident from the Penrose diagram.

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The categories of this paper are: chao-dyn
8
The categories of this paper are: hep-ex
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The categories of this paper are: q-alg
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The categories of this paper are: stat
1
The categories of this paper are: cs
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The categories of this paper are: mtrl-th
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The categories of this paper are: ao-sci
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The categories of this paper are: nucl-th
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The categories of this paper are: astro-ph
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The categories of this paper are: eess
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The categories of this paper are: econ
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The categories of this paper are: atom-ph
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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: solv-int
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The categories of this paper are: adap-org