Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: If time is a local observable, then Hawking radiation is unitary   In the usual formulation of quantum theory, time is a global classical
evolution parameter, not a local quantum observable. On the other hand, both
canonical quantum gravity (which lacks fundamental time-evolution parameter)
and the principle of spacetime covariance (which insists that time should be
treated on an equal footing with space) suggest that quantum theory should be
slightly reformulated, in a manner that promotes time to a local observable.
Such a reformulated quantum theory is unitary in a more general sense than the
usual quantum theory. In particular, this promotes the non-unitary Hawking
radiation to a unitary phenomenon, which avoids the black-hole information
paradox.

19
The categories of this paper are: eess
26
The categories of this paper are: bayes-an
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
30
The categories of this paper are: q-alg
35
The categories of this paper are: mtrl-th
0
The categories of this paper are: hep-ph
4
The categories of this paper are: cond-mat
27
The categories of this paper are: comp-gas
2
The categories of this paper are: math
18
The categories of this paper are: econ
36
The categories of this paper are: cmp-lg
8
The categories of this paper are: hep-ex
1
The categories of this paper are: cs
32
The categories of this paper are: atom-ph