Top pair production at a future $e^+ e^-$ machine in a composite Higgs scenario

International audienceThe top quark plays a central role in many New Physics scenarios and inunderstanding the details of Electro-Weak Symmetry Breaking. In the short- andmid-term future, top-quark studies will mainly be driven by the experiments atthe Large Hadron Collider. Exploration of top quarks will, however, be anintegral part of particle physics studies at any future facility and an $e^+e^-$ collider will have a very comprehensive top-quark physics program. Wediscuss the possibilities of testing NP in the top-quark sector within acomposite Higgs scenario through deviations from the Standard Model in top pairproduction for different Centre-of-Mass energy options of a future $e^+e^-$machine. In particular, we focus on precision studies of the top-quark sectorat a CM energy ranging from 370 GeV up to 3 TeV