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Abstract

Free electrons can recombine with ions by either radiative, dielectronic or three-body recombination. In this contribution we discuss variants of these fundamental processes which can occur in dense photonic, electronic and atomic environments. First, dielectronic recombination is generalized to the case where two atomic centers participate in the process. In this situation, the incident electron is captured at one center with simultaneous excitation of a neighboring ion, atom or molecule which subsequently decays via photo-emission. Modifications of radiative recombination in the presence of a strong laser field are discussed afterward. Various relativistic effects, arising from a high energy of the incoming electron and its strong coupling to the intense laser field, are found to clearly manifest themselves in the photo-emission spectra. Finally, we consider three-body "recombination" (i.e. annihilation) of an electron and a positron in the presence of a spectator electron. The process leads to emission of just a single photon and can compete with the usual annihilation into two photons at very high electron densities.