Nächste Punkte in der Riemannschen Geometrie.
Natural tensor fields of type on the tangent and cotangent bundles of a semi-Riemannian manifold
Naturally reductive homogeneous spaces and generalized Heisenberg groups
Negative Curvature and Embedded Eigenvalues.
Nets on a Riemannian manifold and finite-dimensional approximations of the Laplacian [Book]
New examples of manifolds with negative curvature
New Examples of Manifolds with Strictly Positive Curvature.
New Examples of Weakly Symmetric Spaces.
New results concerning the number of small eigenvalues on Riemann surfaces.
Nodal sets of eigenfunctions on Riemannian manifolds.
Non-existence of Continuous Convex Functions on Certain Riemannian Manifolds.
Nonhomogeneous Riemannian 3-manifolds with distinct constant Ricci eigenvalues
We extend a construction by K. Yamato [Ya] to obtain new explicit examples of Riemannian 3-manifolds as in the title. Some of these examples have an interesting geometrical interpretation.
Non-hyperbolic closed geodesics.
Non-negative curvature obstructions in cohomogeneity one and the Kervaire spheres
In contrast to the homogeneous case, we show that there are compact cohomogeneity one manifolds that do not support invariant metrics of non-negative sectional curvature. In fact we exhibit infinite families of such manifolds including the exotic Kervaire spheres. Such examples exist for any codimension of the singular orbits except for the case when both are equal to two, where existence of non-negatively curved metrics is known.
Non-split almost complex and non-split Riemannian supermanifolds
Non-split almost complex supermanifolds and non-split Riemannian supermanifolds are studied. The first obstacle for a splitting is parametrized by group orbits on an infinite dimensional vector space. For almost complex structures, the existence of a splitting is equivalent to the existence of local coordinates in which the almost complex structure can be represented by a purely numerical matrix, i.e. containing no Grassmann variables. For Riemannian metrics, terms up to degree 2 are allowed in...
Nonuniqueness for the heat flow of harmonic maps
Note on an inequality