Speaker
Description
By combining the techniques of open quantum systems with GR, it is possible to derive an evolution equation, usually called master equation, that predicts the effective dynamics of a matter system under the influence of gravity, where the latter is treated as environment. In the talk, the master equation derived in arXiv:2206.06397 for gravitationally induced decoherence of a scalar field using Ashtekar variables is applied to the one-particle sector, motivated by the prospect of measuring similar decoherence effects in astroparticles such as neutrinos. Here, we will present the steps required to extract the effective dynamics of a single scalar particle from the field-theoretic master equation: After a projection to the single particle space, the resulting evolution equation is connected to Feynman diagrams through which the underlying field theory of linearised gravity coupled to a scalar field can be interpreted as an effective field theory. Making use of this link, a UV renormalisation is sketched. In a final step, different approximations that cast the master equation into a completely positive one are compared, the resulting decoherence of the single scalar particle is analysed, and possible applications are discussed.
