Null-Plane Invariance of Hamiltonian Null-Plane Dynamics

Abstract

Relativistic Hamiltonian few-body dynamics [1, 2] involves two unitary representations of the Poincaré group on the Hilbert space H of physical states, with and without interactions. These two representations, U(Λ, a) and U ₀(Λ, a), coincide for a kinematic subgroup H. The “Hamiltonians” are the generators not in the Lie algebra of the kinematic subgroup. The kinematic subgroup of null-plane dynamics leaves the null-plane z·x≡x ⁰ + x ₃ = 0 invariant.