Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Entanglement entropy production in gravitational collapse: covariant
  regularization and solvable models   We study the dynamics of vacuum entanglement in the process of gravitational
collapse and subsequent black hole evaporation. In the first part of the paper,
we introduce a covariant regularization of entanglement entropy tailored to
curved spacetimes; this regularization allows us to propose precise definitions
for the concepts of black hole "exterior entropy" and "radiation entropy." For
a Vaidya model of collapse we find results consistent with the standard
thermodynamic properties of Hawking radiation. In the second part of the paper,
we compute the vacuum entanglement entropy of various spherically-symmetric
spacetimes of interest, including the nonsingular black hole model of Bardeen,
Hayward, Frolov and Rovelli-Vidotto and the "black hole fireworks" model of
Haggard-Rovelli. We discuss specifically the role of event and trapping
horizons in connection with the behavior of the radiation entropy at future
null infinity. We observe in particular that $(i)$ in the presence of an event
horizon the radiation entropy diverges at the end of the evaporation process,
$(ii)$ in models of nonsingular evaporation (with a trapped region but no event
horizon) the generalized second law holds only at early times and is violated
in the "purifying" phase, $(iii)$ at late times the radiation entropy can
become negative (i.e. the radiation can be less correlated than the vacuum)
before going back to zero leading to an up-down-up behavior for the Page curve
of a unitarily evaporating black hole.

17
The categories of this paper are: q-fin
10
The categories of this paper are: q-bio
14
The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph
34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph
4
The categories of this paper are: cond-mat
20
The categories of this paper are: acc-phys
0
The categories of this paper are: hep-ph
22
The categories of this paper are: chao-dyn
23
The categories of this paper are: solv-int
25
The categories of this paper are: patt-sol
15
The categories of this paper are: nucl-ex
21
The categories of this paper are: adap-org
37
The categories of this paper are: supr-con
13
The categories of this paper are: quant-ph