Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Excitation of an inertial Unruh detector in the Minkowski vacuum: a
  numerical calculation using spherical modes   We consider the excitation of a finite-length inertial Unruh detector in the
Minkowski vacuum with an adiabatic switch on of the interaction in the infinite
past and a sudden switch off at finite times, and obtain the excitation
probability via a numerical calculation using the expansion of the quantum
field in spherical modes. We evaluate first the excitation probabilities for
the final states of the field with one particle per mode, and then we sum over
the modes. An interesting feature is that, despite of the inertial trajectory
and of the vacuum state of the field, the multipole components of the
excitation probability are time-dependent quantities. We make clear how the
multipole sum yields the time-independent probability characteristic to an
inertial trajectory. In passing, we point out that the excitation probability
for a sudden switch on of the interaction in the infinite past is precisely
twice as large as that for an adiabatic switch on. The procedure can be easily
extended to obtain the response of the detector along radial trajectories in
spherically symmetric spacetimes.

7
The categories of this paper are: hep-th
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
13
The categories of this paper are: quant-ph
32
The categories of this paper are: atom-ph
6
The categories of this paper are: astro-ph
14
The categories of this paper are: math-ph
16
The categories of this paper are: stat
29
The categories of this paper are: funct-an
9
The categories of this paper are: nlin
12
The categories of this paper are: nucl-th
4
The categories of this paper are: cond-mat
0
The categories of this paper are: hep-ph
2
The categories of this paper are: math
23
The categories of this paper are: solv-int
22
The categories of this paper are: chao-dyn