In mathematical Platonism, a mathematical cousain of Platonism proper numbers are seen as ideas that are outside of the phenomenal world. It's an obscure doctrine
Consider, the mathematical apparatus describing QM; this uses a hilbert space of states and this is an infinite dimensional space; although it is dependent upon spacetime it is not itself within it in anyway; it supervenes on it.
Can this be used as circumstantial evidence for mathematical Platonism? Or should we argue that this is merely consequence of using mathematics to describe QM.
(Though the latter seems plausible, this can't quite be the case; consider Classical Mechanics, this is also described by mathematics; yet the the primary quantities of position, mass and vocify have a direct physical analogue; this is no where near the case for QM).