  We explore the influence of turbulence on the transport of energetic
particles by using test-particle simulations. We compute parallel and
perpendicular diffusion coefficients for two-component turbulence, isotropic
turbulence, a model based on Goldreich-Sridhar scaling, noisy reduced
magnetohydrodynamic turbulence, and a noisy slab model. We show that diffusion
coefficients have a similar rigidity dependence regardless which turbulence
model is used and, thus, we conclude that the influence of turbulence on
particle transport is not as strong as originally thought. Only fundamental
quantities such as particle rigidity and the Kubo number are relevant. In the
current paper we also confirm the unified nonlinear transport theory for noisy
slab turbulence. To double-check the validity and accuracy of our numerical
results, we use a second test-particle code. We show that both codes provide
very similar results confirming the validity of our conclusions.
