Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Negative energy states in the Reissner-Nordstr\"om metric   We consider electrogeodesics on which the energy $E<0$ in the
Reissner-Nordstr\"{o}m metric. It is shown that outside the horizon there is
exactly one turning point inside the ergoregion for such particles. This
entails that such a particle passes through an infinite chain of black-white
hole regions or terminates in the singularity. These properties are relevant
for two scenarios of high energy collisions in which the presence of white
holes is essential.

33
The categories of this paper are: plasm-ph
27
The categories of this paper are: comp-gas
15
The categories of this paper are: nucl-ex
4
The categories of this paper are: cond-mat
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
13
The categories of this paper are: quant-ph
26
The categories of this paper are: bayes-an
14
The categories of this paper are: math-ph
17
The categories of this paper are: q-fin
30
The categories of this paper are: q-alg
1
The categories of this paper are: cs