Quantum Electrodynamics on the Poincare Group

A general scheme of construction and analysis of physical fields on the various homogeneous spaces of the Poincar\'{e} group is presented. Different parametrizations of the field functions and harmonic analysis on the homogeneous spaces are studied. It is shown that a direct product of Minkowski spacetime and two-dimensional complex sphere is the most suitable homogeneous space for the subsequent physical applications. The Lagrangian formalism and field equations on the Poincar\'{e} group are considered. A boundary value problem for the relativistically invariant system is defined. General solutions of this problem are expressed via an expansion in hyperspherical harmonics on the complex two-sphere. A physical sense of the boundary conditions is discussed. The boundary value problems of the same type are studied for the Dirac and Maxwell fields. In turn, general solutions of these problems are expressed via convergent Fourier type series. Field operators, quantizations, causal commutators and vacuum expectation values of time ordered products of the field operators are defined for the Dirac and Maxwell fields, respectively. Interacting fields and inclusion of discrete symmetries into the framework of quantum electrodynamics on the Poincar\'{e} group are discussed