5 papers
On a Riemannian invariant of Chen type
Teodor Oprea
In [6] we proved Chen's inequality regarded as a problem of constrained maximum. In this paper we introduce a Riemannian invariant obtained from Chen's invariant, replacing the sec…
A new obstruction to minimal isometric immersions into a real space form
Teodor Oprea
In the theory of minimal submanifold, the following problem is fundamental: when does a given Riemannian manifold admit (or does not admit) a minimal isometric immersion into an Eu…
On a geometric inequality
Teodor Oprea
As we showed in [3], a geometric inequality can be regarded as an optimization problem. In this paper we find another proof for a Chen's inequality,regarding the Ricci curvature [2…
Chen's inequality in Lagrangian case
Teodor Oprea
In the theory of submanifolds, the following problem is fundamental: to establish simple relationships between the main intrinsic invariants and the main extrinsic invariants of th…
H-Convex Riemannian Submanifolds
Constantin Udriste, Teodor Oprea
Having in mind the well known model of Euclidean convex hypersurfaces [4], [5], and the ideas in [1] many authors defined and investigate convex hypersurfaces of a Riemannian manif…