The unitary correlation operator method from a similarity renormalization group perspective

[1] and references therein), was devised as a means to de-scribe the correlations induced by the short-range repul-sion and the tensor force of modern realistic NN interac-tions by an explicit unitary transformation. One obtains a phase-shift equivalent correlated interaction VUCOM which exhibits a dramatically improved convergence behavior in practical calculations, resulting from a pre-diagonalization of the interaction in momentum space, as shown for the 3S1 partial wave in Fig. 1. This observation provides a first heuristic link to the sim-ilarity renormalization group (SRG) approach. Following Wegner’s formulation of the SRG [2], one can evolve the many-body Hamiltonian towards a band-diagonal structure by solving the flow equation dHα d