Maximal Acceleration Corrections to the Lamb Shift of One-Electron Atoms

The maximal acceleration corrections to the Lamb shift of one--electron atoms are calculated starting from the Dirac equation and splitting the spinor into large and small components. The results depend on $Z^8$ and a cut-off $\Lambda$. Sizeable values are obtained even at Z=1 for $\Lambda\sim a_0/2$, where $a_0$ is the Bohr radius. These values are compatible with theoretical and experimental results.