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How often does the Unruh-DeWitt detector click? Regularisation by a spatial profile

Jorma Louko·Alejandro Satz
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Abstract

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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Jorma Louko, Alejandro Satz. 2006-10-10. How often does the Unruh-DeWitt detector click? Regularisation by a spatial profile. https://doi.org/10.1088/0264-9381%2F23%2F22%2F015

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