Caslav Brukner

2021-10-26

Caslav Brukner

University of Vienna, Austria

Talk title: Falling through masses in superposition: quantum reference frames for indefinite metrics

Abstract: The current theories of quantum physics and general relativity alone do not allow us to study situations where the gravitational source is quantum. In my talk, I will propose a strategy to determine the dynamics of probe quantum systems in the presence of mass configurations in superposition, and thus an indefinite spacetime metric, using quantum reference frame (QRF) transformations. In particular, I will show that one can use an extension of the current QRF formalism to move to a reference frame in which the metric becomes definite even if the initial spacetime metrics in the superposition are not connected by diffeomorphism. Assuming the covariance of the dynamical laws under the QRF transformation, this will transform the problem of the dynamics of probe quantum systems in indefinite metrics into a physically equivalent problem of the dynamics in a definite metric.

Time: July 4, Monday, 21:30-22:30 (CST, UTC+8)