Eigenvalue estimates for Dirac operators with parallel characteristic torsion

Autor: Mario Kassuba, Ilka Agricola, Thomas Friedrich
Rok vydání: 2008
Předmět:
Zdroj: Differential Geometry and its Applications. 26:613-624
ISSN: 0926-2245
DOI: 10.1016/j.difgeo.2008.04.010
Popis: Assume that the compact Riemannian spin manifold $(M^n,g)$ admits a $G$-structure with characteristic connection $\nabla$ and parallel characteristic torsion ($\nabla T=0$), and consider the Dirac operator $D^{1/3}$ corresponding to the torsion $T/3$. This operator plays an eminent role in the investigation of such manifolds and includes as special cases Kostant's ``cubic Dirac operator'' and the Dolbeault operator. In this article, we describe a general method of computation for lower bounds of the eigenvalues of $D^{1/3}$ by a clever deformation of the spinorial connection. In order to get explicit bounds, each geometric structure needs to be investigated separately; we do this in full generality in dimension 4 and for Sasaki manifolds in dimension 5.
Comment: 16 pages, 4 figures
Databáze: OpenAIRE