ИСТИНА

The mathematical basis for the theory of quasielastic (e,2e) reactions is more or less well-established. In particular, it includes the procedure of renormalization of higher Born terms which are presented by formally divergent integrals, if the basis of plane waves is employed. Most of the calculations are carried out within the plane/distorted wave first Born approximations, but divergences of higher Born contributions make such calculations not reliable without the rigorous mathematical theory. In the case of the (e,2e) laser-assisted reactions, most of calculations are also carried out within the first Born approximation with the Volkov functions instead of plane waves. Nevertheless, a number of issues remain open, when formulating the theory in analogy with the time-independent one. We list the main problems in the report.