Nielsensche Realisierungssätze für Seifertfaserungen.
Nilpotent subgroups of the group of fibre homotopy equivalences.
Let ξ = (E, p, B, F) be a Hurewicz fibration. In this paper we study the space LG(ξ) consisting of fibre homotopy self equivalences of ξ inducing by restriction to the fibre a self homotopy equivalence of F belonging to the group G. We give in particular conditions implying that π1(LG(ξ)) is finitely generated or that L1(ξ) has the same rational homotopy type as aut1(F).