Bulletin of the London Mathematical Society Advance Access originally published online on June 3, 2009
Bulletin of the London Mathematical Society 2009 41(4):683-690; doi:10.1112/blms/bdp042
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© 2009 London Mathematical Society
A brief note on the spectrum of the basic Dirac operator
Mathematics Department
Faculty of Sciences II
Lebanese University
P.O. Box 90656
Fanar-Matn
Lebanon
ghabib@ul.edu.lb
Department of Mathematics
Texas Christian University
TCU Box 298900
Fort Worth, TX 76180
USA
Received 21 September 2008.
In this paper, we prove the invariance of the spectrum of the basic Dirac operator defined on a Riemannian foliation (M,
) with respect to a change of bundle-like metric. We then establish new estimates for its eigenvalues on spin flows in terms of the ONeill tensor and the first eigenvalue of the Dirac operator on M. We discuss examples and also define a new version of the basic Laplacian whose spectrum does not depend on the choice of bundle-like metric.
2000 Mathematics Subject Classification 53C12 (primary), 53C21, 58J50, 58J60 (secondary).