The sectional curvature, Ricci curvature, and scalar curvature for a product generalized Sasakian space form are obtained. Furthermore, the Chen-Ricci inequality and the Hineva inequality are established for submanifolds of a product generalized Sasakian space form, including product Sasakian, product cosymplectic, and product Kenmotsu space forms. The equality cases are also discussed.
Verma et al. (Wed,) studied this question.