  We investigate the resonance interaction energy between two uniformly
accelerated identical atoms, interacting with the scalar field or the
electromagnetic field in the vacuum state, in the reference frame
coaccelerating with the atoms. We assume that one atom is excited and the other
in the ground state, and that they are prepared in their correlated symmetric
or antisymmetric state. Using perturbation theory, we separate, at the second
order in the atom-field coupling, the contributions of vacuum fluctuations and
radiation reaction field to the energy shift of the interacting system. We show
that only the radiation reaction term contributes to the resonance interaction
between the two atoms, while Unruh thermal fluctuations, related to the vacuum
fluctuations contribution, do not affect the resonance interatomic interaction.
We also show that the resonance interaction between two uniformly accelerated
atoms, recently investigated in the comoving (locally inertial) frame, can be
recovered in the coaccelerated frame, without the additional assumption of the
Fulling-Davies-Unruh temperature for the quantum fields (as necessary for the
Lamb-shift, for example). This indicates, in the case considered, the
equivalence between the coaccelerated frame and the locally inertial frame.

Quantum Physics;General Relativity and Quantum Cosmology