A Geometric-Algebra Treatment of the Feynman–Vernon–Hellwarth Space in the Two-State Problem

Pauli algebra is reviewed and then related to Dirac’s braket algebra and a generalization of the Wigner–Jordan operators in the two-state problem. A method similar to the Feynman–Vernon–Hellwarth (FVH) method is developed from the Pauli algebra density operator. This yields a true geometric algebra treatment of the FVH space. The equation of motion for the density operator is developed from the Schrödinger equation. A general solution in laboratory coordinates is given. Ensemble effects are discussed.