 Hestenes refers to this as the "real Pauli–Schrödinger theory" to emphasize that this theory reduces to the Schrödinger theory if the term that includes the magnetic field is dropped.The relativistic quantum wavefunction is sometimes expressed as a spinor field, i.e.where formula_54 is a bivector, and
where, according to its derivation by David Hestenes, formula_56 is an even multivector-valued function on spacetime, formula_57 is a unimodular spinor (or “rotor”), and formula_58 and formula_59 are scalar-valued functions.