Theoretical results for top quark physics at a linear electron positron
collider will be presented. The predictions for the
top quark decay rate and distributions are described, including
the influence of radiative corrections and of extensions of the
Standard Model. The production cross section for top quarks
through
electron positron annihilation and photon photon fusion is large
throughout, which may allow an accurate determination of the top
magnetic moment as well as interesting measurement of CP violating
observables. The cross section in the threshold region as well as the
momentum distribution of top quarks and their decay products will lead
to an accurate determination of the top quark mass, the interquark
potential, and eventually even of the Yukawa coupling to the Higgs
boson. It is shown that higher order corrections through
final state interaction and relativistic corrections are small and
sufficiently under control.
