Department of Mathematics, Masaryk University, Faculty of Science, Janackovo nam. 2a, 602 00 Brno, Czech Republic
We consider symmetries on filtered manifolds and we study the $|1|$-graded parabolic geometries in more details. We discuss the existence of symmetries on the homogeneous models and we conclude some simple observations on the general curved geometries.
AMSclassification. 53C25, 53C15, 53B15.
Keywords. $CR-$structures, almost contact structures, $f$-structure with complemented frames.