There are a few groups of researchers currently working on reformulating relativity as de Sitter relativity: *R. Aldrovandi, J. P. Beltran Almeida, J. G. Pereira, http://arxiv.org/abs/0805.2584 *S. Cacciatori, V. Gorini, A. Kamenshchik, http://arxiv.org/abs/0807.3009 *Han-Ying Guo, Chao-Guang Huang, Zhan Xu, Bin Zhou, http://arxiv.org/abs/hep-th/0405137 Ignazio Licata and Leonardo Chiatti say Fantappié-Arcidiacono theory of relativity was the same thing as the recent work on de Sitter relativity. http://arxiv.org/abs/0808.1339 This is described in the wikipedia article: http://en.wikipedia.org/wiki/De_Sitter_invariant_special_relativity Can someone answer these questions from the article's talk page and related pages: *Is de Sitter Relativity any different from other work on Doubly Special Relativity ? *Is Fantappié-Arcidiacono theory of relativity the same as de Sitter relativity ? *Is de Sitter relativity just the same as special relativity using different coordinates ? *Does it contradict results in cosmology ? *Does de Sitter general relativity make any sense ?