  An interesting connection between special relativity and quantum mechanics
was put forward by Louis de Broglie, about 60 years ago, who focused on the
link between synchronization in a rotating frame and the quantization of the
angular momentum. Here we generalise his approach to curved spacetime, using
the gravitoelectromagnetic analogy, which can be applied to describe the weak
gravitational field around rotating sources, and give a new interpretation of
the results.
