Einstein's general relativity was not deduced from postulates. It is a not-even-wrong empirical concoction - a malleable combination of ad hoc equations and fudge factors allowing Einsteinians to predict anything they want:

https://www.quora.com/What-are-the-p...ral-Relativity
What are the postulates of General Relativity? Alexander Poltorak, Adjunct Professor of Physics at the CCNY: "In 2005 I started writing a paper, "The Four Cornerstones of General Relativity on which it doesn't Rest." Unfortunately, I never had a chance to finish it. The idea behind that unfinished article was this: there are four principles that are often described as "postulates" of General Relativity:

1. Principle of general relativity

2. Principle of general covariance

3. Equivalence principle

4. Mach principle

The truth is, however, that General Relativity is not really based on any of these "postulates" although, without a doubt, they played important heuristic roles in the development of the theory." [END OF QUOTATION]

Sometimes Einsteinians call Einstein's 1915 final ad hoc equations "postulates" (we all live in Einstein's schizophrenic world, don't we):

http://math.stanford.edu/~schoen/tri.../lecture_3.pdf
"Postulates of General Relativity
Postulate 1: A spacetime (M^4, g) is a Riemannian 4-manifold M^4 with a Lorentzian metric g.
Postulate 2: A test mass beginning at rest moves along a timelike geodesic. (Geodesic equation) ...
Postulate 3: Einstein equation is satisfied. (Einstein equation) ..." [END OF QUOTATION]

General relativity had not predicted that the gravitational waves travel at the speed of light but was tweaked to make that prediction:

Arthur Eddington: "The statement that in the relativity theory gravitational waves are propagated with the speed of light has, I believe, been based entirely upon the foregoing investigation; but it will be seen that it is only true in a very conventional sense. If coordinates are chosen so as to satisfy a certain condition which has no very clear geometrical importance, the speed is that of light; if the coordinates are slightly different the speed is altogether different from that of light. The result stands or falls by the choice of coordinates and, so far as can be judged, the coordinates here used were purposely introduced in order to obtain the simplification which results from representing the propagation as occurring with the speed of light. The argument thus follows a vicious circle." The Mathematical Theory of Relativity, pp. 130-131 https://www.amazon.com/Mathematical-.../dp/0521091659

In order to be consistent with dark matter, general relativity needs four fudge factors:

"Verlinde's calculations fit the new study's observations without resorting to free parameters – essentially values that can be tweaked at will to make theory and observation match. By contrast, says Brouwer, conventional dark matter models need four free parameters to be adjusted to explain the data." https://www.newscientist.com/article...f-dark-matter/

How many fudge factors LIGO conspirators needed to model the nonexistent gravitational waves is a deep mystery:

"Cornell professors Saul Teukolsky, astrophysics, and Larry Kidder, astronomy, played an instrumental role in the first detection of gravitational waves, a century after Albert Einstein predicted their existence in his theory of general relativity. [...] The LIGO and Virgo group confirmed that these gravitational waves had come from the collision of black holes by comparing their data with a theoretical model developed at Cornell. Teukolsky and the Cornell-founded Simulation of eXtreme Spacetimes collaboration group have been developing this model since 2000, according to the University." http://cornellsun.com/2016/02/10/cor...of-relativity/

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