Searches for new physics with top- and bottom-quark signatures using the ATLAS detector

High-mass resonances or new particles decaying into top- and/or bottom-quark + X are predicted in many new physics scenarios including extended gauge models, extra dimensions, 2HDM, etc. The vector-like quarks (VLQs), preferentially coupled to the third generation SM quarks, are also predicted e.g, in composite Higgs models as a “natural” way to stabilise the Higgs boson mass. This talk highlights recent ATLAS searches with the third generation quarks using LHC Run 1 data. First LHC Run-2 results will be included if available.