L. Amour & B. Grebert & J. C. Guillot
The dressed mobile atoms and ions
(318K, pdf)

ABSTRACT.  We consider free atoms and ions in $\R^3$ interacting with the 
quantized electromagnetic field. Because of the translation 
invariance we consider the reduced hamiltonian associated with the 
total momentum. After introducing an ultraviolet cutoff we prove 
that the reduced hamiltonian for atoms has a ground state if the 
coupling constant and the total momentum are sufficiently small. 
In the case of ions an extra infrared regularization is needed. We 
also consider the case of the hydrogen atom in a constant magnetic 
field. Finally we determine the absolutely continuous spectrum of 
the reduced hamiltonian. 
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