Second-order corrections to the non-commutative Klein-Gordon equation   with a Coulomb potential
  We improve the previous study of the Klein-Gordon equation in a non-commutative space-time as applied to the Hydrogen atom to extract the energy levels, by considering the second-order corrections in the non-commutativity parameter. Phenomenologically we show that non-commutativity is the source of lamb shift corrections. 
Slimane Zaim, Lamine Khodja and Yazid Delenda
math-ph hep-ph hep-th math.MP