Searches for Vector-like Quarks, tt‾ and tb resonances with the ATLAS Detector

Various extensions of the Standard Model predict the existence of new types of quarks or bosons. We report on searches for vector-like quarks decaying to a Z   boson and a top quark or bottom quark and new resonances decaying to a top-antitop pair and a top-antibottom pair. Several of these searches include the use of boosted top quark reconstruction techniques. These searches use the data sample recorded in 2012 at s=8 TeV centre-of-mass energy by the ATLAS experiment at CERN's Large Hadron Collider. In these searches no evidence for new physics is observed.