Real hypersurfaces with pseudo-parallel normal Jacobi operator in   complex two-plane Grassmannians
  The objective of the present paper is to prove the non-existence of real hypersurface with pseudo-parallel normal Jacobi operator in complex two-plane Grassmannians. As a corollary, we show that there does not exist any real hypersurface with semi-parallel or recurrent normal Jacobi operator in complex two-plane Grassmannians. This answers a question considered in [Monatsh Math, 172 (2013), 167-178] in negative. 
Avik De and Tee-How Loo
math.DG