pave the way for continued progress in theoretical nuclear structure studies. Figure 3 shows,
symbolically, three pillars of modern research with nuclei: experimentation, analytic theory,
and supercomputing [1]. This figure also illustrates the main challenges faced by the modern
nuclear many-body problem: the need for a validated, high quality input, the importance of
many-body dynamics, and the impact of open reaction and decay channels. For excellent
collections of papers on burning questions in nuclear structure and reaction theory, I refer the
reader to the two recent focus issues of J. Phys.