Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A path integral formulation for particle detectors: the Unruh-DeWitt
  model as a line defect   Particle detectors are an ubiquitous tool for probing quantum fields in the
context of relativistic quantum information (RQI). We formulate the
Unruh-DeWitt (UDW) particle detector model in terms of the path integral
formalism. The formulation is able to recover the results of the model in
general globally hyperbolic spacetimes and for arbitrary detector trajectories.
Integrating out the detector's degrees of freedom yields a line defect that
allows one to express the transition probability in terms of Feynman diagrams.
Inspired by the light-matter interaction, we propose a gauge invariant detector
model whose associated line defect is related to the derivative of a Wilson
line. This is another instance where nonlocal operators in gauge theories can
be interpreted as physical probes for quantum fields.

1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th
30
The categories of this paper are: q-alg
35
The categories of this paper are: mtrl-th
29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn
3
The categories of this paper are: physics
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
17
The categories of this paper are: q-fin
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
9
The categories of this paper are: nlin
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
33
The categories of this paper are: plasm-ph