  By means of dynamical mean field theory calculations, it was recently
discovered that kinks generically arise in strongly correlated systems, even in
the absence of external bosonic degrees of freedoms such as phonons. However,
the physical mechanism behind these kinks remained unclear. On the basis of the
perturbative and numerical renormalization group theory, we herewith identify
these kinks as the effective Kondo energy scale of the interacting lattice
system which is shown to be smaller than the width of the central peak.
