# What is mathematical definition of a strong gravity?

Mathematical definition of a weak gravity is simple $g=\frac{GM}{r^2}$ but what is mathematical definition of a strong gravity? (blackhole-like or close to a blackhole-like object)

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it's far more complicated than just that, what you're looking for is the framework of general relativity! –  Schlomo Steinbergerstein Apr 20 '13 at 10:18
"mathematical definition of a stronger gravity?" the simple answer is, a larger M. –  Ataraxia Apr 20 '13 at 13:56
@ZettaSuro: or the strong coupling limit (in the ADM formalism) when $G\to\infty$ --- i.e., gravity becomes "really, really strong". –  Alex Nelson Apr 20 '13 at 16:46