Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Particle detectors, geodesic motion, and the equivalence principle   It is shown that quantum particle detectors are not reliable probes of
spacetime structure. In particular, they fail to distinguish between inertial
and non-inertial motion in a general spacetime. To prove this, we consider
detectors undergoing circular motion in an arbitrary static spherically
symmetric spacetime, and give a necessary and sufficient condition for the
response function to vanish when the field is in the static vacuum state. By
examining two particular cases, we show that there is no relation, in general,
between the vanishing of the response function and the fact that the detector
motion is, or is not, geodesic. In static asymptotically flat spacetimes,
however, all rotating detectors are excited in the static vacuum. Thus, in this
particular case the static vacuum appears to be associated with a non-rotating
frame. The implications of these results for the equivalence principle are
considered. In particular, we discuss how to properly formulate the principle
for particle detectors, and show that it is satisfied.

21
The categories of this paper are: adap-org
20
The categories of this paper are: acc-phys
13
The categories of this paper are: quant-ph
8
The categories of this paper are: hep-ex
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
34
The categories of this paper are: chem-ph
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con
1
The categories of this paper are: cs
30
The categories of this paper are: q-alg
6
The categories of this paper are: astro-ph