explanatorily closed. Research at Perimeter Institute for Theoretical Physics is supported in pan by the Government of Canada through NSERC and by the Province of Ontario through MRI. [I] L. de Broglie. Solvay Conference. 1928, Electrons et Photons: Rapport% et Discussions du Cinquieme Conseil de Physique tenu a Brux

ahead of publication. Research at Perimeter Institute for Theoretical Physics is sup- ported in part by the Government of Canada through NSERC and by the Province of Ontario through MRI. A Relationship to other approaches In this appendix I would like to contrast the results we have found to hold for tc-Minkowski spac

erent perspective[23]. Research at Perimeter Institute for Theoretical Physics is supported in part by the Government of Canada through NSERC and by the Province of Ontario through MRI. References [1] G. Amelino-Camelia, Relativity in space-times with short-distance structure governed by an observer-independent (Plan