Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Black hole lasers, a mode analysis   We show that the black hole laser effect discovered by Corley & Jacobson
should be described in terms of frequency eigenmodes that are spatially bound.
The spectrum contains a discrete and finite set of complex frequency modes
which appear in pairs and which encode the laser effect. In addition, it
contains real frequency modes that form a continuous set when space is
infinite, and which are only elastically scattered, i.e., not subject to any
Bogoliubov transformation. The quantization is straightforward, but the
calculation of the asymptotic fluxes is rather involved. When the number of
complex frequency modes is small, our expressions differ from those given
earlier. In particular, when the region between the horizons shrinks, there is
a minimal distance under which no complex frequency mode exists, and no
radiation is emitted. Finally, we relate this effect to other dynamical
instabilities found for rotating black holes and in electric fields, and we
give the conditions to get this type of instability.

31
The categories of this paper are: ao-sci
3
The categories of this paper are: physics
23
The categories of this paper are: solv-int
12
The categories of this paper are: nucl-th
36
The categories of this paper are: cmp-lg
17
The categories of this paper are: q-fin
21
The categories of this paper are: adap-org
34
The categories of this paper are: chem-ph
27
The categories of this paper are: comp-gas
30
The categories of this paper are: q-alg
26
The categories of this paper are: bayes-an
37
The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
24
The categories of this paper are: dg-ga
16
The categories of this paper are: stat