2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/52277We briefly review a recent progress in constructing the low-energy effective action in ${\cal N}=2,4$ super Yang-Mills theories. Using superfield methods we study the one- and two-loop contributions to the effective action in the Coulomb and non-Abelian phases. General structure of low-energy corrections to the effective action is discussed.LaTeX, 6 p., Rinton style file attached. Based on the talk given by I.L. Buchbinder at the International Conference "Quantum Field Theory Under the Influence of External Conditions - QFEXT03", University of Oklahoma, Norman, USA, September 15-19, 2003, to be appeared in the Proceedings. References correctedHigh Energy Physics - Theorytext