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Related papers: Energy-Momentum tensor on foliations

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We give a new upper bound for the smallest eigenvalues of the Dirac operator on a Riemannian flow carrying transversal Killing spinors. We derive an estimate on Sasakian and on 3-dimensional manifolds and partially classify those satisfying…

Differential Geometry · Mathematics 2010-10-07 Nicolas Ginoux , Georges Habib

We prove a new lower bound for the first eigenvalue of the Dirac operator on a compact Riemannian spin manifold by refined Weitzenb\"ock techniques. It applies to manifolds with harmonic curvature tensor and depends on the Ricci tensor.…

Differential Geometry · Mathematics 2007-05-23 Thomas Friedrich , Klaus-Dieter Kirchberg

In this paper, we extend the Hijazi inequality, involving the Energy-Momentum tensor, for the eigenvalues of the Dirac operator on $Spin^c$ manifolds without boundary. The limiting case is then studied and an example is given.

Differential Geometry · Mathematics 2015-05-19 Roger Nakad

In this paper, we consider a compact Riemannian manifold whose boundary is endowed with a Riemannian flow. Under a suitable curvature assumption depending on the O'Neill tensor of the flow, we prove that any solution of the basic Dirac…

Differential Geometry · Mathematics 2015-07-09 Fida El Chami , Nicolas Ginoux , Georges Habib , Roger Nakad

On a compact surface endowed with any $\Spinc$ structure, we give a formula involving the Energy-Momentum tensor in terms of geometric quantities. A new proof of a B\"{a}r-type inequality for the eigenvalues of the Dirac operator is given.…

Differential Geometry · Mathematics 2012-04-04 Georges Habib , Roger Nakad

We prove a lower bound for the first eigenvalue of the Dirac operator on a compact Riemannian spin manifold depending on the scalar curvature as well as a chosen Codazzi tensor. The inequality generalizes the classical estimate from [2].

Differential Geometry · Mathematics 2007-09-07 Th. Friedrich , E. C. Kim

In this paper, we extend the Hijazi type inequality, involving the Energy-Momentum tensor, to the eigenvalues of the Dirac operator on complete Riemannian Spin$^c$ manifolds without boundary and of finite volume. Under some additional…

Differential Geometry · Mathematics 2011-01-25 Roger Nakad

Given a Riemannian spin^c manifold whose boundary is endowed with a Riemannian flow, we show that any solution of the basic Dirac equation satisfies an integral inequality depending on geometric quantities, such as the mean curvature and…

Differential Geometry · Mathematics 2016-12-13 Fida Chami , Nicolas Ginoux , Georges Habib , Roger Nakad

We study the Dirac spectrum on compact Riemannian spin manifolds $M$ equipped with a metric connection $\nabla$ with skew torsion $T\in\Lambda^3M$ by means of twistor theory. An optimal lower bound for the first eigenvalue of the Dirac…

Differential Geometry · Mathematics 2013-11-05 Ilka Agricola , Julia Becker-Bender , Hwajeong Kim

We prove a new upper bound for the first eigenvalue of the Dirac operator of a compact hypersurface in any Riemannian spin manifold carrying a non-trivial twistor spinor without zeros on the hypersurface. The upper bound is expressed as the…

Differential Geometry · Mathematics 2016-01-20 Nicolas Ginoux , Georges Habib , Simon Raulot

On $Spin^c$ manifolds, we study the Energy-Momentum tensor associated with a spinor field. First, we give a spinorial Gauss type formula for oriented hypersurfaces of a $Spin^c$ manifold. Using the notion of generalized cylinders, we derive…

Differential Geometry · Mathematics 2015-05-20 Roger Nakad

We get optimal lower bounds for the eigenvalues of the submanifold Dirac operator on locally reducible Riemannian manifolds in terms of intrinsic and extrinsic expressions. The limiting-cases are also studied. As a corollary, one gets…

Differential Geometry · Mathematics 2020-10-27 Yongfa Chen

In this paper, we prove Kirchberg inequalities for any kahler spin foliations. Their limiting cases are then characterized as being transversal minimal Einstein foliations. The key point is to introduce the transversal kahlerian twistor…

Differential Geometry · Mathematics 2009-11-13 Georges Habib

We show the convergence properties of the eigenvalues of the Dirac operator on a spin manifold with a Riemannian flow when the metric is collapsed along the flow.

Differential Geometry · Mathematics 2024-06-17 Georges Habib , Ken Richardson

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…

Differential Geometry · Mathematics 2013-11-06 Ilka Agricola , Thomas Friedrich , Mario Kassuba

We derive new lower bounds for the first eigenvalue of the Dirac operator of an oriented hypersurface $\Sigma$ bounding a noncompact domain in a spin asymptotically flat manifold (M n , g) with nonnegative scalar curvature. These bounds…

Differential Geometry · Mathematics 2023-04-26 Simon Raulot

In a previous paper we proved a lower bound for the spectrum of the Dirac operator on quaternionic Kaehler manifolds. In the present article we show that the only manifolds in the limit case, i.e. the only manifolds where the lower bound is…

dg-ga · Mathematics 2009-10-30 W. Kramer , U. Semmelmann , G. Weingart

We prove new lower bounds for the first eigenvalue of the Dirac operator on compact manifolds whose Weyl tensor or curvature tensor, respectively, is divergence free. In the special case of Einstein manifolds, we obtain estimates depending…

Differential Geometry · Mathematics 2009-11-07 Thomas Friedrich , Klaus-Dieter Kirchberg

We give a lower bound for the eigenvalues of the Dirac operator on a compact domain of a Riemannian spin manifold under the $\MIT$ bag boundary condition. The limiting case is characterized by the existence of an imaginary Killing spinor.

Differential Geometry · Mathematics 2015-06-26 Simon Raulot

We give a survey of results relating the restricted holonomy of a Riemannian spin manifold with lower bounds on the spectrum of its Dirac operator, giving a new proof of a result originally due to Kirchberg.

Differential Geometry · Mathematics 2007-11-12 Marcos Jardim , Rafael F. Leao
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