Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the Origin of the Outgoing Black Hole Modes   The question of how to account for the outgoing black hole modes without
drawing upon a transplanckian reservoir at the horizon is addressed. It is
argued that the outgoing modes must arise via conversion from ingoing modes. It
is further argued that the back-reaction must be included to avoid the
conclusion that particle creation cannot occur in a strictly stationary
background. The process of ``mode conversion" is known in plasma physics by
this name and in condensed matter physics as ``Andreev reflection" or ``branch
conversion". It is illustrated here in a linear Lorentz non-invariant model
introduced by Unruh. The role of interactions and a physical short distance
cutoff is then examined in the sonic black hole formed with Helium-II.

36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
29
The categories of this paper are: funct-an
27
The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph
24
The categories of this paper are: dg-ga
11
The categories of this paper are: hep-lat
34
The categories of this paper are: chem-ph
3
The categories of this paper are: physics
22
The categories of this paper are: chao-dyn
6
The categories of this paper are: astro-ph
30
The categories of this paper are: q-alg
20
The categories of this paper are: acc-phys
17
The categories of this paper are: q-fin