Speaker
Description
Models for gravitationally induced decoherence can be formulated in the framework of open quantum systems, where gravity is chosen as the environment and quantized together with the system under consideration. Existing phenomenological models often take the Lindblad equation as a starting point for the master equation, while from the perspective of quantum gravity approaches, an underlying microscopic model from which a field-theoretical master equation can be derived seems to be the more accessible route. In the first part, we briefly discuss the tasks to be accomplished in principle to formulate such open quantum models in the framework of loop quantum gravity (LQG), as well as the challenges that come along with it, focusing on the similarities and differences with existing models of gravitationally induced decoherence with linearized gravity. These include the role of physical dynamical reference frames in open relativistic quantum systems, the renormalization of the master equation, and the specific quantization method used in LQG-inspired models. In the second part, recent first steps and results on some of the relevant steps discussed in the first part are presented. This involves an open QFT model formulated in terms of Ashtekar-Barbero variables, the usual classical starting point for LQG, but which is still based on a standard Fock quantization, a special choice of so-called geometrical clocks as a reference frame, and a renormalization of the master equation based on QFT techniques.
