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Related papers: A mod 2 index theorem for pin$^-$ manifolds

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We consider Dirac operators on odd-dimensional compact spin manifolds which are twisted by a product bundle. We show that the space of connections on the twisting bundle which yield an invertible operator has infinitely many connected…

Differential Geometry · Mathematics 2015-10-28 Francesco Bei , Nils Waterstraat

We obtain a vanishing theorem for the kernel of a Dirac operator on a Clifford module twisted by a sufficiently large power of a line bundle, whose curvature is non-degenerate at any point of the base manifold. In particular, if the base…

Differential Geometry · Mathematics 2007-05-23 Maxim Braverman

A Dirac operator on a complete manifold is Fredholm if it is invertible outside a compact set. Assuming a compact group to act on all relevant structure, and the manifold to have a warped product structure outside such a compact set, we…

Differential Geometry · Mathematics 2023-03-20 Peter Hochs , Hang Wang

We study the topological band theory of time reversal invariant topological insulators and interpret the topological $\mathbb{Z}_2$ invariant as an obstruction in terms of Stiefel--Whitney classes. The band structure of a topological…

Mathematical Physics · Physics 2016-04-12 Ralph M. Kaufmann , Dan Li , Birgit Wehefritz-Kaufmann

We propose a Z$_2$ index theorem for a generic topological superconductor in class D. Introducing a particle-hole symmetry breaking term depending on a parameter and regarding it as a coordinate of an extra dimension, we define the index of…

Superconductivity · Physics 2010-12-23 T. Fukui , T. Fujiwara

When the index bundle of a longitudinal Dirac type operator is transversely smooth, we define its Chern character in Haefliger cohomology and relate it to the Chern character of the $K-$theory index. This result gives a concrete connection…

Geometric Topology · Mathematics 2007-05-23 Moulay Benameur , James Heitsch

We consider the assembly map for principal bundles with fiber a countable discrete group. We obtain an index-theoretic interpretation of this homomorphism by providing a tensor-product presentation for the module of sections associated to…

K-Theory and Homology · Mathematics 2022-11-02 Jens Kaad , Valerio Proietti

Using Liu's modular invariance method and its odd-dimensional extension by Han and Yu, we establish new Witten rigidity theorems for the generalized Witten genus of twisted Dirac operators on even-dimensional spin$^c$ manifolds and twisted…

Differential Geometry · Mathematics 2025-12-19 Jianyun Guan , Kefeng Liu , Yong Wang

We give a formulation of a deformation of Dirac operator along orbits of a group action on a possibly non-compact manifold to get an equivariant index and a K-homology cycle representing the index. We apply this framework to non-compact…

Differential Geometry · Mathematics 2021-03-02 Hajime Fujita

The purpose of this paper is to compute determinant index bundles of certain families of Real Dirac type operators on Klein surfaces as elements in the corresponding Grothendieck group of Real line bundles in the sense of Atiyah. On a Klein…

Algebraic Geometry · Mathematics 2013-09-04 Christian Okonek , Andrei Teleman

We study two special cases of the equivariant index defined in part I of this series. We apply this index to deformations of Spin$^c$-Dirac operators, invariant under actions by possibly noncompact groups, with possibly noncompact orbit…

Differential Geometry · Mathematics 2016-03-11 Peter Hochs , Yanli Song

We give a proof of the cobordism invariance of the index of elliptic pseudodifferential operators on sigma-compact manifolds, where, in the non-compact case, the operators are assumed to be multiplication outside a compact set. We show…

K-Theory and Homology · Mathematics 2016-09-07 Catarina Carvalho

Let (M,g) be a compact Riemannian spin manifold. The Atiyah-Singer index theorem yields a lower bound for the dimension of the kernel of the Dirac operator. We prove that this bound can be attained by changing the Riemannian metric g on an…

Differential Geometry · Mathematics 2016-03-03 Bernd Ammann , Mattias Dahl , Emmanuel Humbert

We prove an asymptotic bound on the eta invariant of a family of coupled Dirac operators on an odd dimensional manifold. In the case when the manifold is the unit circle bundle of a positive line bundle over a complex manifold, we obtain…

Differential Geometry · Mathematics 2018-11-05 Nikhil Savale

We propose an alternative formulation of the $Z_2$ topological index for quantum spin Hall systems and band insulators when time reversal invariance is not broken. The index is expressed in terms of the Chern numbers of the bands of the…

Mesoscale and Nanoscale Physics · Physics 2009-11-01 Rahul Roy

This article is concerned with the analysis of Dirac operators $D$ twisted by ramified Euclidean line bundles $(Z,\mathfrak{l})$-motivated by their relation with harmonic $\mathbf{Z}/2\mathbf{Z}$ spinors, which have appeared in various…

Differential Geometry · Mathematics 2026-04-15 Gorapada Bera , Thomas Walpuski

We give a proof of the index theorem of lattice Wilson--Dirac operators, which states that the index of a twisted Dirac operator on the standard torus is described in terms of the corresponding lattice Wilson--Dirac operator. Our proof is…

Mathematical Physics · Physics 2020-09-09 Yosuke Kubota

The paper combines several fortunate mini miracles to achieve its two objectives. These were woven together in a several year's effort to answer a question raised by Iz Singer a decade ago. Our answer is accessible to the topologist, to the…

K-Theory and Homology · Mathematics 2018-03-21 James Simons , Dennis Sullivan

Let M be a compact manifold with a fixed spin structure \chi. The Atiyah-Singer index theorem implies that for any metric g on M the dimension of the kernel of the Dirac operator is bounded from below by a topological quantity depending…

Differential Geometry · Mathematics 2011-07-21 Bernd Ammann , Mattias Dahl , Emmanuel Humbert

We prove an analogue for even dimensional manifolds of the Atiyah-Patodi-Singer twisted index theorem for trivialized flat bundles. We show that the eta invariant appearing in this result coincides with the eta invariant by Dai and Zhang up…

Differential Geometry · Mathematics 2010-10-13 Zhizhang Xie