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TrickyDicky said:This might also be helpful:
E. C. Zeeman
Causality Implies the Lorentz Group.
J. Math. Phys. April 1964 Volume 5, Issue 4, pp. 490-493
Along this line of reasoning...
A.A. Robb's (1914) axiomatic approach (using the notion of an ordering relation 'after') should be mentioned
http://en.wikipedia.org/wiki/Alfred_Robb
http://books.google.com/books?id=vp...hthUGyh&sig=csSzPceSNPGd4uoGmPMUKloDtU0&hl=en (comment by Torretti)
There are implicit assumptions of continuity.
friend said:I found the following paper on the arXiv:
http://arxiv.org/abs/1005.4172
This makes reference to Rafael Sorkin's (1987) "Causal Sets", a fundamentally-discrete approach to Quantum Gravity
http://en.wikipedia.org/wiki/Causal_sets
Aimless said:I remember hearing in a talk once upon a time that knowing the casual structure of spacetime was sufficient to give you the metric up to a (constant?) scale factor; however, I've been unable to track down a reference for that statement.
See Finkelstein's (1969) "Space-Time Code"
http://prola.aps.org/abstract/PR/v184/i5/p1261_1
http://streaming.ictp.trieste.it/preprints/P/68/019.pdf [preprint]
"The causal order C determines the conformal structure of space-time, or nine of the
ten components of the metric. The measure on spacetime fixes the tenth component."
[per spacetime event in 3+1 dimensions] (p. 1262, or p.3 in the preprint)