Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: How often does the Unruh-DeWitt detector click? Regularisation by a
  spatial profile   We analyse within first-order perturbation theory the instantaneous
transition rate of an accelerated Unruh-DeWitt particle detector whose coupling
to a massless scalar field on four-dimensional Minkowski space is regularised
by a spatial profile. For the Lorentzian profile introduced by Schlicht, the
zero size limit is computed explicitly and expressed as a manifestly finite
integral formula that no longer involves regulators or limits. The same
transition rate is obtained for an arbitrary profile of compact support under a
modified definition of spatial smearing. Consequences for the asymptotic
behaviour of the transition rate are discussed. A number of stationary and
nonstationary trajectories are analysed, recovering in particular the Planckian
spectrum for uniform acceleration.

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The categories of this paper are: bayes-an
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The categories of this paper are: chao-dyn
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The categories of this paper are: patt-sol
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The categories of this paper are: atom-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: nucl-th
3
The categories of this paper are: physics
37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph
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The categories of this paper are: cs
35
The categories of this paper are: mtrl-th
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The categories of this paper are: quant-ph
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The categories of this paper are: astro-ph
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The categories of this paper are: adap-org
4
The categories of this paper are: cond-mat
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The categories of this paper are: nlin