The Dirac-Coulomb Problem for the $\kappa$-Poincare Quantum Group
The recently introduced $\kappa$-Poincare-Dirac equation is gauged to treat the $\kappa$-Dirac-Coulomb problem. For the resulting equation, we prove that the perturbation to first order in the quantum group parameter vanishes identically. The second order perturbation is singular, but assuming a heuristic cut-off allows a qualitative estimate of the quantum group parameter.