Asao Arai
Spectral Analysis of an Effective Hamiltonian in Nonrelativistic Quantum Electrodynamics
(261K, pdf)

ABSTRACT.  We investigate spectral properties of an effective Hamiltonian which is obtained as a scaling limit 
of the Pauli-Fierz model in nonrelativistic quantum electrodynamics. 
The Lamb shift of a hydrogen-like atom is derived as the lowest order approximation (in the fine structure 
constant) 
of an energy level shift of the effective Hamiltonian.