Structural Origins of the Uncertainty Principle: Space-Time Symmetry, Quantum Non-Commutativity, and the Heisenberg Group
ming Cheng
Where does Heisenberg’s uncertainty principle come from? We show that it requires two physical inputs, neither sufficient alone. Space-time symmetry decides which observables are conjugate: momentum generates translations, so [x,p] is constant. Quantum structure, namely the complex structure of Hilbert space, makes observables into generators, so conjugate observables do not commute. The two combine as a non-trivial central extension, the Heisenberg group. At this level the physical and mathematical origins coincide. The uncertainty principle is the Cauchy–Schwarz inequality on the Kähler state space, which is equivalently the quantum Cramér–Rao limit on detecting a symmetry transformation. Phase-space geometry alone is not an origin, and infinite dimension is the price of the canonical bound, not its source.
•Oct 13, 2026•0 citations