“…Over the last decade, fluctuation theory stimulated the study of potential and spectral theory for symmetric Lévy processes (and in particular those with completely monotone jumps); see, e.g., [7,8,9,10,12,14,24,25,26,33,34,35,36,37,38,39,41,53,54,55,72] and the references therein. There are, however, very few papers where similar problems are studied for asymmetric processes, see [27,28,40,63,75]. The results of the present article may therefore stimulate the development of potential theory and spectral theory for asymmetric Lévy processes.…”