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Related papers: Eigenvalue pinching on $\text{spin}^c$ manifolds

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We use the Dirac operator technique to establish sharp distance estimates for compact spin manifolds under lower bounds on the scalar curvature in the interior and on the mean curvature of the boundary. In the situations we consider, we…

Differential Geometry · Mathematics 2024-05-22 Simone Cecchini , Rudolf Zeidler

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

We generalize the well-known lower estimates for the first eigenvalue of the Dirac operator on a compact Riemannian spin manifold proved by Th. Friedrich (1980) and O. Hijazi (1986, 1992). The special solutions of the Einstein-Dirac…

Differential Geometry · Mathematics 2007-05-23 Thomas Friedrich , Eui Chul Kim

In this paper, we consider the eigenvalue problem of Dirac operator on a compact Riemannian manifold isometrically immersed into Euclidean space and derive some extrinsic estimates for the sum of arbitrary consecutive $n$ eigenvalues of the…

Differential Geometry · Mathematics 2024-02-23 Lingzhong Zeng

Consider the class of n-dimensional Riemannian spin manifolds with bounded sectional curvatures and diameter, and almost non-negative scalar curvature. Let r=1 if n=2,3 and r=2^{[n/2]-1}+1 if n\geq 4. We show that if the square of the Dirac…

Differential Geometry · Mathematics 2008-02-25 Bernd Ammann , Chad Sprouse

In this paper, we proved a compactness result about Riemannian manifolds with an arbitrary pointwisely pinched Ricci curvature tensor.

Differential Geometry · Mathematics 2007-07-03 Hui-Ling Gu

In this paper, we first establish an $S^1$-equivariant index theorem for Spin$^c$ Dirac operators on $\mathbb{Z}/k$ manifolds, then combining with the methods developed by Taubes \cite{MR998662} and Liu-Ma-Zhang \cite{MR1870666,MR2016198},…

Differential Geometry · Mathematics 2011-04-21 Bo Liu , Jianqing Yu

Using Weitzenb\"ock techniques on any compact Riemannian spin manifold we derive inequalities that involve a real parameter and join the eigenvalues of the Dirac operator with curvature terms. The discussion of these inequalities yields…

Differential Geometry · Mathematics 2009-11-10 K. -D. Kirchberg

We study boundary value problems for the Dirac operator on Riemannian Spin$^c$ manifolds of bounded geometry and with noncompact boundary. This generalizes a part of the theory of boundary value problems by C. B\"ar and W. Ballmann for…

Differential Geometry · Mathematics 2017-05-17 Nadine Große , Roger Nakad

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

In this paper we consider the Hilbert-Einstein-Dirac functional, whose critical points are pairs, metrics-spinors, that satisfy a system coupling the Riemannian and the spinorial part. Under some assumptions, on the sign of the scalar…

Differential Geometry · Mathematics 2022-03-29 Ali Maalaoui , Vittorio Martino

We find a unique torsion free Riemannian spin connection for the natural Killing metric on the quantum group $C_q[SL_2]$, using a recent frame bundle formulation. We find that its covariant Ricci curvature is essentially proportional to the…

Quantum Algebra · Mathematics 2007-05-23 Shahn Majid

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

It is known that, for Dirac operators on Riemann surfaces twisted by line bundles with Hermitian-Einstein connections, it is possible to obtain estimates for the first eigenvalue in terms of the topology of the twisting bundle \cite{JL2}.…

Differential Geometry · Mathematics 2013-10-15 Rafael F. Leão

Under some dimension restrictions, we prove that totally umbilical hypersurfaces of Spin$^c$ manifolds carrying a parallel, real or imaginary Killing spinor are of constant mean curvature. This extends to the Spin$^c$ case the result of O.…

Differential Geometry · Mathematics 2019-11-15 Nadine Große , Roger Nakad

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

Since the first work of Thomas Friedrich showing that isometric immersions of Riemann surfaces are related to spinors and the Dirac equation, various works appeared generalizing this approach to more general Spin-manifolds, in particular…

Differential Geometry · Mathematics 2019-03-27 Rafael de Freitas Leão , Samuel Augusto Wainer

We study the question of existence of a Riemannian metric of positive scalar curvature metric on manifolds with the Sullivan-Baas singularities. The manifolds we consider are Spin and simply connected. We prove an analogue of the…

Differential Geometry · Mathematics 2014-11-11 Boris Botvinnik

In this note we consider versions of both Ricci and sectional curvature pinching for Riemannian manifold with density. In the Ricci curvature case the main result implies a diameter estimate that is new even for compact shrinking Ricci…

Differential Geometry · Mathematics 2015-01-27 William Wylie

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