There is only one time
We draw a picture of physical systems that allows us to recognize what “time” is by requiring consistency with the way that time enters the fundamental laws of Physics. Elements of the picture are two non-interacting and yet entangled quantum systems, one of which acting as a clock. In this setting, employing the Page and Wootters mechanism with tools from large-N quantum approaches, we show that there is not a “quantum time”, possibly opposed to a “classical” one; there is only one time, and it is a manifestation of entanglement.
Talk’s slides: 21ROMAtalk_compressed