As a follow-up of last week's seminar I will consider a test particle interacting with a gravitational field quantized in the weak-field (linear) approximation. I will review the recent theory of Parikh, Wilczek and Zahariade [1] describing an arm of a gravitational wave detector interacting with this kind of quantized gravitational field. I will show, as Parikh et al also do, that an effective nonlinear friction force follows analogously to the way ordinary friction appears in the Caldeira-Leggett theory of quantum Brownian motion. I will further discuss the random force from the vacuum on the test particle, and heating of the gravitational vacuum by the interaction with the test particle. Finally I will discuss if this approach does or does not allow to estimate entropy production in the gravitational vacuum.
The seminar will be given in hybrid format, on-line at
https://kth-se.zoom.us/j/68888238166
but may be given as a whiteboard talk, hence sound and video quality may leave something to be desired.
[1] Maulik Parikh, Frank Wilczek and George Zahariade, "Signatures of the quantization of gravity at gravitational wave detectors", Phys. Rev. D 104, 046021 (2021)