Speaker
Caslav Brukner
Description
Every observation in physics is made with respect to a frame
of reference. In practise, we use real physical systems as
reference frames, and as such they obey quantum mechanical
laws. I will introduce a general method to quantise
reference frame transformations, which generalises the usual
reference frame transformation to a "superposition of
coordinate transformations". I will describe how states,
measurements, and dynamical evolutions transform between
different quantum reference frames. While entanglement and
superposition will be shown to be frame-dependent features,
the form of the dynamical physical laws (e.g. the
Schrödinger equation) remain the same in all frames, which
generalises the notion of covariance of physical laws to
quantum reference frames. I will end with two applications
of our results: a definition of the rest frame for a quantum
particle in a superposition of velocities, and a resolution
of an old problem of identifying the qubit for a
relativistic spin particle.
Primary author
Prof.
Caslav Brukner