Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: State reduction and energy extraction from black holes   I show that attempts to detect Hawking quanta would reduce the quantum state
to one containing ultra-energetic incoming particles; couplings of these to
other systems would extract ultra-high energies from the gravitational
collapse. As the collapse proceeds, these energies grow exponentially, rapidly
become trans-Planckian, and quantum-gravitational effects must enter.

6
The categories of this paper are: astro-ph
4
The categories of this paper are: cond-mat
18
The categories of this paper are: econ
26
The categories of this paper are: bayes-an
10
The categories of this paper are: q-bio
23
The categories of this paper are: solv-int
3
The categories of this paper are: physics
9
The categories of this paper are: nlin
22
The categories of this paper are: chao-dyn
11
The categories of this paper are: hep-lat
35
The categories of this paper are: mtrl-th
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th