18 citations · 20 across the 3 of their papers we have counts for
5 papers
Killing forms on G2 and Spin7 manifolds
Uwe Semmelmann
Killing forms on Riemannian manifolds are differential forms whose covariant derivative is totally skew-symmetric. We show that on a compact manifold with holonomy G2 or Spin7 any…
An upper bound for a Hilbert polynomial on quaternionic Kahler manifolds
Uwe Semmelmann, Gregor Weingart
In this article we prove an upper bound for a Hilbert polynomial on quaternionic Kaehler manifolds of positive scalar curvature. As corollaries we obtain bounds on the quaternionic…
Conformal Killing forms on Riemannian manifolds
U. Semmelmann
Conformal Killing forms are a natural generalization of conformal vector fields on Riemannian manifolds. They are defined as sections in the kernel of a conformally invariant first…
Cosmic strings and strings in gravitational waves
H. -J. Schmidt, U. Semmelmann
We consider strings with the Nambu action as extremal surfaces in a given space-time, thus, we ignore their back reaction. Especially, we look for strings sharing one symmetry with…
Vanshing Theorems for Quaternionic Kaehler Manifolds
Uwe Semmelmann, Gregor Weingart
We discuss a peculiar interplay between the representation theory of the holonomy group of a Riemannian manifold, the Weitzenboeck formula for the Hodge-Laplace operator on forms a…