  Differential cross sections of $t \overline{t}$ production have been measured
by the ATLAS experiment at the LHC. Monte Carlo calculations provide an overall
good modeling of all measured distributions, except for the transverse momentum
of the top quark, for which all the generators at the next-to-leading order
produce harder spectra. These measurements have been also included in the PDF
fits, contributing to a sensible reduction of the gluon PDF uncertainty at
large $x$.
