Kragujevac J. Math. 25 (2003) 139-145.

RELATIONS BETWEEN INTRINSIC AND EXTRINSIC CURVATURES

S. Haesen1, A. Sebekovic2 and L. Verstraelen3

1K.U.Brussel, Vrijheidslaan 17, B-1081 Brussel, Belgium
2University of Kragujevac, Department of Mathematics, Radoja Domanovica 12, 34000 Kragujevac, Serbia and Montenegro
3K.U.Leuven, Celestijnenlaan 200B, B-3001 Heverlee (Leuven), Belgium

Abstract. In some sense reversing the historical traject, in § 1 it will be indicated how all scalar-valued intrinsic curvatures of Riemannian manifolds can be determined in terms of the curvatures of associated Euclidean curves. This involves the consideration of arbitrary-dimensional normal sections of submanifolds in Euclidean spaces and their projections on appropriate subspaces. In terms of such normal sections of Euclidean submanifolds and of such projections, in § 2 some comments will be made concerning general inequalities for Euclidean submanifolds between their scalar curvature and their mean- and normal scalar curvatures.