2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/182533We compute the shear viscosity and the electrical conductivity in gauge theories with massive fermions at leading order in the large N_f expansion. The calculation is organized using the 1/N_f expansion of the 2PI effective action to next-to-leading order. We show explicitly that the calculation is gauge fixing independent and consistent with the Ward identity. We find that these transport coefficients depend in a nontrivial manner on the coupling constant and fermion mass. For large mass, both the shear viscosity and the electrical conductivity go to zero.38 pages, typos corrected, JHEP versionHigh Energy Physics - PhenomenologyNuclear Theorytext