Relative locality is a proposed physical phenomenon in which different observers would disagree on whether two
space-time
In physics, spacetime is a mathematical model that combines the three-dimensional space, three dimensions of space and one dimension of time into a single four-dimensional manifold. Minkowski diagram, Spacetime diagrams can be used to visualize S ...
events are coincident. This is in contrast to
special relativity and
general relativity in which different observers may disagree on whether two distant events occur at the same time but if an observer infers that two events are at the same spacetime position then all observers will agree.
When a light signal exchange procedure is used to infer spacetime coordinates of distant events from the travel time of photons, information about the photon's energy is discarded with the assumption that the frequency of light doesn't matter. It is also usually assumed that distant observers construct the same spacetime. This assumption of absolute locality implies that
momentum space is flat. However research into
quantum gravity
Quantum gravity (QG) is a field of theoretical physics that seeks to describe gravity according to the principles of quantum mechanics; it deals with environments in which neither gravitational nor quantum effects can be ignored, such as in the vi ...
has indicated that momentum space might be curved which would imply relative locality.
[''Relative locality: A deepening of the relativity principle'', ]Giovanni Amelino-Camelia
Giovanni Amelino-Camelia (born 14 December 1965, Naples) is an Italian physicist of the University of Naples Federico II who works on quantum gravity.
He is the first proposer of doubly special relativity that is the idea of introducing the Pla ...
, Laurent Freidel, Jerzy Kowalski-Glikman, Lee Smolin, International Journal of Modern Physics D, Vol. 20, No. 14 (2011) 2867–2873, World Scientific Publishing Company, , To regain an absolute arena for invariance one would combine spacetime and momentum space into a phase space.
References
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External links
Beyond space-time: Welcome to phase space New Scientist, 8 August 2011, issue 2824
Quantum gravity
Concepts in physics
Special relativity
General relativity