Doubly Twisted Product Contact CR-Submanifolds in Quasi-Sasakian Manifolds

Abstract

In current paper, we have shown that a doubly twisted product
Contact CR-submanifolds f T b N N  of quasi-Sasakian manifold such
that the structure vector field  is tangential to N ,  does not exist. We
have also shown that a doubly twisted product Contact CR-submanifolds
f T b N N  of Sasakian or cosympletic manifold such that the structure
vector field  is tangential to N ,  does not exist.