Resumen de Fixed point sets of parabolic isometries of CAT(0)-spaces

Koji Fujiwara, Takashi Nagano, Takashi Shioya

• We study the fixed point set in the ideal boundary of a parabolic isometry of a proper CAT(0)-space. We show that the radius of the fixed point set is at most $\pi/2$, and study its centers. As a consequence, we prove that the set of fixed points is contractible with respect to the Tits topology.