  Recent inclusive and differential cross section measurements of the
associated production of top quark pairs with gauge bosons or heavy-flavor jets
are reported. A search for physics beyond the standard model in the top quark
sector is also presented. All measurements are based on data samples of
proton-proton collisions at $\sqrt{s}=13$ TeV collected by the ATLAS and CMS
experiments at the CERN LHC. No significant deviation from the standard model
predictions is observed.
