A Gel'fand-Yaglom Spin-3/2 Equation with Three Invariant Electromagnetic Couplings
Relativistic equations for massive spin-3/2 particles face well-known subsidiary-constraint problems in external fields. Within the Gel’fand–Yaglom formalism, we construct a parity-invariant first-order theory based on an extended 28-component Lorentz representation with four repeated bispinor sectors. Nilpotency of th...