  We present explicit expressions for the high-frequency asymptotic behavior of
electron self-energy of general quantum impurity models, which may be useful
for improving the convergence of dynamical mean-field calculations and for the
analytic continuation of the electron self-energy. We also give results,
expressed in more physical terms, for the two-orbital and three-orbital
rotationally invariant Slater-Kanamori interactions, in order to facilitate
calculations of transition metal oxides.
