On invariant submanifolds of lorentzian para-sasakian manifolds

الملخص EN

We consider semiparallel and 2-semiparallel invariant submanifolds of Lorentzian para-Sasakian manifolds.

We show that these submanifolds are totally geodesic.

We also consider invariant submanifolds of Lorentzian para-Sasakian manifolds satisfying the conditions Z (X, Y ) • α = 0 and Z (X, Y ) ∇α = 0 with τ = n (n−1).

Under these conditions, we prove that the submanifolds are totally geodesic.