Measurements of the top--antitop quark pair production charge asymmetry in the dilepton channel are presented using data corresponding to an integrated luminosity of 20.3 $fb^{-1}$ from pp collisions at a center-of-mass energy of $\sqrt{s}=8\,$ TeV collected with the ATLAS detector at the Large Hadron Collider at CERN. Inclusive and differential measurements as a function of the invariant mass, transverse momentum, and longitudinal boost of the $t\bar{t}$ system are performed both in the full phase space and in a fiducial phase space closely matching the detector acceptance. Two observables are studied: $A_{ll}^{C}$ based on the selected leptons and $A_{t\bar{t}}^C$ based on the reconstructed $t\bar{t}$ final state. The inclusive asymmetries are measured in the full phase space to be $A_{ll}^{C} =0.008 \pm 0.006$ and $A_{t\bar{t}}^C = 0.021 \pm 0.016$, which are in agreement with the Standard Model predictions of $A_{ll}^{C} = 0.0064 \pm 0.0003$ and $A_{t\bar{t}}^C = 0.0111 \pm 0.0004$.
The top-antitop inclusive asymmetry in the fiducial volume.