Infrared exponents and running coupling of SU(N) Yang-Mills theories

We present approximate solutions for the gluon and ghost propagators as well as the running coupling in Landau gauge Yang-Mills theories, We solve the corresponding Dyson-Schwinger equations in flat Euclidean spacetime without any angular approximation. This supplements recently obtained results employing a four-torus, i.e., a compact spacetime manifold, as infrared regulator. We confirm previous findings deduced from an extrapolation with tori of different volumes: the gluon propagator is weakly vanishing in the infrared and the ghost propagator is highly singular. For non-vanishing momenta our propagators are in remarkable agreement with recent lattice calculations. (C) 2002 Elsevier Science B.V. All rights reserved.