Is the top-quark mass insensitive to the ultraviolet dynamics of the Nambu model?

In this paper we check directly if the infrared fixed-point (IRFP) behavior of the Nambu model makes the prediction for the top-quark mass insensitive to its strong ultraviolet dynamics. This is done by comparing the top-quark mass obtained from the Schwinger-Dyson equation for the Nambu model with that obtained from the renormalization-group analysis of the effective Higgs theory in the large-$N_c$ limit. Our results indicate that in this approximation the IRFP does make the top-quark mass insensitive to the unstable high-energy behavior of the Higgs theory.