This Topical Review is unconventional: rather than presenting past achievements, it aims at reviewing future options for theory of nuclear fission. As we discussed in the Introduction, numerous reviews and books that discuss experimental and theoretical aspects of nuclear fission exist Schunck and Robledo (2016); Bertsch et al. (2015); Andreyev et al. (2017); Talou et al. (2018); Schmidt and Jurado (2018); Krappe and Pomorski (2012); Younes et al. (2019). The interested reader is encouraged to consult these references for more extensive and detailed information. The goal of the present work was to lay down our opinions on directions of future research in theory of nuclear fission. While this task is challenging, we found it useful to talk about research directions that seem to be promising and at the same time may be long overdue.
We will be most happy if our ideas are picked up by enthusiastic researchers working in this domain of nuclear physics, and even more, if they attract new talent into this area. Undoubtedly, many proposed directions will require concerted efforts of large collaborations, and we hope that this Topical Review will contribute to fostering those.
Beyond phenomenological modelling, the theoretical description of nuclear fission requires novel ideas on how to treat the incredible complexity of the phenomenon in a manageable and physically meaningful way. To be implemented, many of those ideas require advanced computations. In this document, we call for performing baseline work on developing quantified interactions/functionals for fission studies; identifying the essential ingredients in fission theory; utilizing extensions of current models of non-adiabatic large-amplitude collective motion; developing a comprehensive approach to fission observables; making connection between models based on the intrinsic-system concept and the symmetry-conserved observables; and for realistic modelling of the compound nucleus as well as of the specific nuclear states that form gateways to fission. Each and every one of these projects may in the future become a challenging research direction. Together, they may lead to a major advance of the field.