Convergence of the regularized Kohn-Sham iteration in Banach spaces

The Kohn-Sham iteration of generalized density-functional theory on Banach spaces with Moreau-Yosida regularized universal Lieb functional and an adaptive damping step is shown to converge to the correct ground-state density. This result demands state spaces for (quasi)densities and potentials that are uniformly convex with modulus of convexity of power type. The Moreau-Yosida regularization is adapted to match the geometry of the spaces and some convex analysis results are extended to this type of regularization. Possible connections between regularization and physical effects are pointed out as well. The proof of convergence presented here (Theorem 23) contains a critical mistake that has been noted and fixed for the finite-dimensional case in arXiv:1903.09579. Yet, the proposed correction is not straightforwardly generalizable to a setting of infinite-dimensional Banach spaces. This means the question of convergence in such a case is still left open. We present this draft as a collection of techniques and ideas for a possible altered, successful demonstration of convergence of the Kohn--Sham iteration in Banach spaces.