U(1)
Electromagnetism
Unit complex numbers form the symmetry of light and charge. Their Hopf fibration fills a sphere with circles that link every other circle exactly once: the geometry of a single magnetic charge.
- provedThe twistor incidence of loop quantum gravity is the Hopf map S³ → S², in the formal library.
- provedThe linking number of two Hopf fibres is a 2 × 2 determinant, exact, at zero tolerance.