Confronting the improvements to track reconstruction algorithms for the ATLAS inner detector with run 2 data from the LHC

With the increase in energy of the LHC to $\sqrt{s}=13$~TeV for run 2, events with dense environments become much more abundant. These environments are characterized by charged particle separations of the order of ATLAS inner detector sensor dimensions and can be created by the decay of boosted objects. The performance of the track reconstruction in these extreme conditions is presented using Monte Carlo Simulation. Further, the inefficiency of the track reconstruction in the core of jets as a function of the transverse momentum of the jet between 200 GeV and 1600 GeV, using proton-proton data collected by the ATLAS experiment at a center-of-mass energy of $\sqrt{s}=13$~TeV is discussed.