Time-dependent renormalized natural orbital theory for laser-driven correlated few-body quantum dynamics

Reduced density matrix functional theory (RDMFT) can be formulated in terms of the eigenfunctions of the 1-RDM, the ``natural orbitals\'\' (NO), leading to natural orbital theory (NOT). In many-body strong-field physics we are mainly interested in timedependent, correlated phenomena far beyond linear response. Hence, a full timedependent version of NOT, i.e., TDNOT, or TDRDMFT, is needed, especially in cases where simpler TDDFT fails [1,2].