id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
work_nppx6ohgxvbrpn6alermuekxi4	D. Giulini	Uniqueness of Simultaneity	2001	18	.pdf	application/pdf	8981	784	73	Absolute simultaneity is specified to be a nontrivial equivalence relation which is invariant under the automorphism Let us point out right at the beginning that our requirements on simultaneity differ slightly from the ones used by Malament and Sarkar & Stachel: they require the simultaneity-defining equivalence relation to be invariant under all causal automorphisms (explained in section 5), whereas we only require Requirement 1 Absolute Simultaneity is a non-trivial Aut-invariant equivalence relation on M each equivalence class of which intersects any physically set [p] := G · p to define a non-trivial G-invariant equivalence relation. Hence Theorem 1 guarantees the existence of a non-trivial Aut-invariant equivalence relation. Theorem 2 Let S be a non-trivial Aut = IGal – invariant equivalence relation clearly are non-trivial AutX -invariant equivalence relations whose classes are Theorem 5 Let X be a foliation of M by timelike straight lines and S a nontrivial AutX = ILorX – invariant equivalence relation on M.	./cache/work_nppx6ohgxvbrpn6alermuekxi4.pdf	./txt/work_nppx6ohgxvbrpn6alermuekxi4.txt