  A path integral approach is used to derive a closed analytical expression for
the Kondo temperature of the SU(4) symmetrical Anderson model. In contrast to
the SU(2) case, the prefactor of the Kondo temperature is found to display a
peculiar orbital energy (gate voltage) dependence, reflecting the presence of
various SU(4) mixed valence fixed points. Our analytical expressions are tested
against and confirmed by numerical renormalization group computations.
