Our research on accelerating time reference frames is now published in Communications Physics!
Relativistic theories made operational approaches for time and space a cornerstone of physics, leading to a drastic change in our view of these concepts. These approaches start from the simple observation that clocks and rods, used to measure time and space, are physical objects and, hence, subject to physical laws. In quantum mechanics, however, while measurements are an essential element, it seems that the theory does not readily allow the description of measurements of time since it contains time as an external parameter. That being said, multiple attempts to introduce a time observable to the theory have been made, the most prominent being a relational framework introduced by Page and Wootters.
In our work, we show unitary dynamics from the perspective of clocks in this framework is not guaranteed. More precisely: quantum dynamics seems non-Hermitian from the perspective of non-inertial quantum clocks. It remains to be investigated whether this is a feature of the framework, revealing a new fundamental characteristic of physics, or a bug, showing the limitations of its use.
You can click here to read the freely available article. Work conducted in collaboration with Amit Te’eni, Bar Y. Peled, Eliahu Cohen, and Yakir Aharonov.