Curved quantum phase space invalidates Hudson's theorem: SU(1,1) systems host non-Gaussian pure states with non-negative Wigner functions beyond coherent states, fundamentally altering how we define classicality in quantum information theory.

Curved quantum phase space invalidates Hudson's theorem: SU(1,1) systems host non-Gaussian pure states with non-negative Wigner functions beyond coherent states, fundamentally altering how we define classicality in quantum information theory.