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This manuscript investigates the curvature and topological properties of certain $\infty$-Einstein Finsler metrics on Finsler metric measure spaces. By imposing symmetry conditions, we construct a series of special metrics and analyze their…

Differential Geometry · Mathematics 2025-07-29 Bin Shen

For spin manifolds with boundary we consider Riemannian metrics which are product near the boundary and are such that the corresponding Dirac operator is invertible when half-infinite cylinders are attached at the boundary. The main result…

Differential Geometry · Mathematics 2014-06-19 Mattias Dahl , Nadine Große

In this paper we prove an initial data rigidity result \`a la Eichmair, Galloway and Mendes (arXiv:2009.09527) using Dirac operator techniques. It applies to initial data sets on spin bands that satisfy the dominant energy condition, a…

Differential Geometry · Mathematics 2023-04-06 Jonathan Glöckle

The aim of the lectures is to introduce first-year Ph.D. students and research workers to the theory of the Dirac operator, spinor techniques, and their relevance for the theory of eigenvalues in Riemannian geometry. Topics: differential…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Giampiero Esposito

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

It is well-known that spin structures and Dirac operators play a crucial role in the study of positive scalar curvature metrics (psc-metrics) on compact manifolds. Here we consider a class of non-spin manifolds with "almost spin" structure,…

Differential Geometry · Mathematics 2023-05-16 Boris Botvinnik , Jonathan Rosenberg

In this paper, we introduce several new secondary invariants for Dirac operators on a complete Riemannian manifold with a uniform positive scalar curvature metric outside a compact set and use these secondary invariants to establish a…

K-Theory and Homology · Mathematics 2021-09-02 Xiaoman Chen , Hongzhi Liu , Hang Wang , Guoliang Yu

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 article, we give results of prescribing scalar and mean curvature functions for metrics either pointwise conformal or conformally equivalent to a Riemannian metric that is equipped on a compact manifold with boundary, with…

Differential Geometry · Mathematics 2023-01-04 Jie Xu

Under standard local boundary conditions or certain global APS boundary conditions, we get lower bounds for the eigenvalues of the Dirac operator on compact spin manifolds with boundary. Limiting cases are characterized by the existence of…

Differential Geometry · Mathematics 2009-10-31 Oussama Hijazi , Sebastian Montiel , Xiao Zhang

We give examples of spin $4$-manifolds with boundary $(M,\partial M)$ such that the boundary $\partial M$ has a positive scalar curvature metric which cannot be extended to a positive scalar curvature metric on $M$ with mean convex…

Differential Geometry · Mathematics 2026-01-08 Steven Rosenberg , Daniel Ruberman , Jie Xu

We study the minimization problem for eigenvalues of the Dirac operator within a fixed conformal class on a closed spin Riemannian manifold. We establish a criterion for the existence of a minimizer for this variational problem, focusing…

Differential Geometry · Mathematics 2026-04-17 Pavel Martynyuk

In his book Mickelsson notices that the infinite-dimensional Grassmannian manifold of Segal and Wilson admits a Spin^c structure and after this he naturally considers the problem of defining a Dirac operator on it. Mickelsson gives a…

Representation Theory · Mathematics 2010-07-27 Vesa Tahtinen

We assume that the manifold with boundary, X, has a Spin_C-structure with spinor bundle S. Along the boundary, this structure agrees with the structure defined by an infinite order integrable almost complex structure and the metric is…

Analysis of PDEs · Mathematics 2011-11-09 Charles L. Epstein

On a compact spin manifold we study the space of Riemannian metrics for which the Dirac operator is invertible. The first main result is a surgery theorem stating that such a metric can be extended over the trace of a surgery of codimension…

Differential Geometry · Mathematics 2011-07-21 Mattias Dahl

We analyze the limit of the spectrum of a geometric Dirac-type operator under a collapse with bounded diameter and bounded sectional curvature. In the case of a smooth limit space B, we show that the limit of the spectrum is given by the…

Differential Geometry · Mathematics 2007-05-23 John Lott

We consider on a spin manifold with boundary a Dirac operator $D_A$ with chiral boundary conditions, twisted by a unitary connection $A$. When $m$ is not in the chiral spectrum of $D_A$, we define an analogue of the Dirichlet-to-Neumann map…

Analysis of PDEs · Mathematics 2025-11-26 Carlos Valero

In this paper, we use localization algebras to study higher rho invariants of closed spin manifolds with positive scalar curvature metrics. The higher rho invariant is a secondary invariant and is closely related to positive scalar…

K-Theory and Homology · Mathematics 2014-05-21 Zhizhang Xie , Guoliang Yu

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

For a Riemannian closed spin manifold and under some topological assumption (non-zero $\hat{A}$-genus or enlargeability in the sense of Gromov-Lawson), we give an optimal upper bound for the infimum of the scalar curvature in terms of the…

Differential Geometry · Mathematics 2007-05-23 Hélène Davaux