2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/107243On the occasion of the 70th birthday of Prof. Adriano Di Giacomo we report on recent numerical computations of the Landau gauge gluon and ghost propagators as well as of a non-symmetric MOM-scheme ghost-gluon vertex in quenched and full lattice QCD. Special emphasis is paid to the Gribov copy problem and to the unquenching effect. The corresponding running coupling α_s(q^2) is found and shown to decrease for q^2 \le 0.3 GeV^2 in the infrared limit. No indication for a non-trivial infrared fixed point is seen in agreement with findings from truncated systems of Dyson-Schwinger equations treated on a four-dimensional torus.contribution to "Sense of Beauty in Physics", Festschrift in honor of Adriano Di Giacomo's 70-th birthdayHigh Energy Physics - Latticetext