Following a study of projective symmetry in Friedmann-Robertson-Walker models in (Hall G S 2000 Class. Quantum Grav. 17 4637), it is shown (theorem 2) that the only conformally flat, perfect fluid spacetimes admitting such symmetry are, essentially, (locally) of the Friedmann-Robertson-Walker type.
|Number of pages||3|
|Journal||Classical and Quantum Gravity|
|Publication status||Published - 2002|