On limitations of the extent of inertial frames in non-commutative relativistic spacetimes

Understand

We study the interplay of non-locality and Lorentz invariance in a version of deformed or doubly special relativity (DSR) based on kappa-Minkowski spacetime.

• We find that Einstein's procedure for an inertial observer to assign coordinates to distant events becomes ambiguous for sufficiently distant events.
• The accuracy to which two clocks can be synchronized turns out to depend on the distance between them.
• These are consequences of the non-commutativity of space and time coordinates or a dependence of the speed of light on energy in relativistic theories.