International Journal of Geometric Methods in Modern Physics, vol.14, no.5, 2017 (SCI-Expanded)
As a generalization of anti-invariant ζ-Riemannian submersions, we introduce semi-invariant ζ-Riemannian submersions from Sasakian manifolds onto Riemannian manifolds. We give examples, investigating the geometry of foliations which arise from the definition of a Riemannian submersion and proving a necessary and sufficient condition for a semi-invariant ζ-Riemannian submersion to be totally geodesic. Moreover, we study semi-invariant ζ-Riemannian submersions with totally umbilical fibers.