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Related papers: Orbifold index and equivariant K-homology

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We establish an S^1-equivariant index theorem for Dirac operators on Z/k-manifolds. As an application, we generalize the Atiyah-Hirzebruch vanishing theorem for S^1-actions on closed spin manifolds to the case of Z/k-manifolds.

Differential Geometry · Mathematics 2007-05-23 Weiping Zhang

We generalize Roe's index theorem for graded generalized Dirac operators on amenable manifolds to multigraded elliptic uniform pseudodifferential operators. The generalization will follow from a local index theorem that is valid on any…

Differential Geometry · Mathematics 2018-06-07 Alexander Engel

We develop a formula for the equivariant index of a twisted Dirac operator on a compact globally hyperbolic spacetime with timelike boundary on which a group acts isometrically, subject to APS boundary conditions. The formula is the same as…

Differential Geometry · Mathematics 2026-02-19 Onirban Islam , Lennart Ronge

We develop notions of twisted spinor bundle and twisted pre-quantum bundle on quasi-Hamiltonian G-spaces. The main result of this paper is that we construct a Dirac operator with index given by positive energy representation of loop group.…

Symplectic Geometry · Mathematics 2016-06-29 Yanli Song

We give a local formula for the index of a transverse Dirac-type operator on a compact manifold with a Riemannian foliation, under the assumption that the Molino sheaf is a sheaf of abelian Lie algebras.

Differential Geometry · Mathematics 2015-03-17 Alexander Gorokhovsky , John Lott

We establish the factorization of Dirac operators on Riemannian submersions of compact spin$^c$ manifolds in unbounded KK-theory. More precisely, we show that the Dirac operator on the total space of such a submersion is unitarily…

K-Theory and Homology · Mathematics 2016-10-11 Jens Kaad , Walter D. van Suijlekom

We show that if a countable discrete group acts properly and isometrically on a spin manifold of bounded Riemannian geometry and uniformly positive scalar curvature, then, under a suitable condition on the group action, the maximal higher…

K-Theory and Homology · Mathematics 2024-09-02 Hao Guo , Zhizhang Xie , Guoliang Yu

We study Dirac operators acting on sections of a Clifford module ${\cal E}$\ over a Riemannian manifold $M$. We prove the intrinsic decomposition formula for their square, which is the generalisation of the well-known formula due to…

High Energy Physics - Theory · Physics 2007-05-23 T. Ackermann , J. Tolksdorf

Let G be a compact, semi-simple Lie group and H a maximal rank reductive subgroup. The irreducible representations of G can be constructed as spaces of harmonic spinors with respect to a Dirac operator on the homogeneous space G/H twisted…

Differential Geometry · Mathematics 2007-05-23 Gregory D. Landweber

We introduce a Banach Lie group $G$ of unitary operators subject to a natural trace condition. We compute the homotopy groups of $G$, describe its cohomology and construct an $S^1$-central extension. We show that the central extension…

K-Theory and Homology · Mathematics 2016-08-29 Pedram Hekmati , Jouko Mickelsson

Fundamental solutions of Dirac type operators are introduced for a class of conformally flat manifolds. This class consists of manifolds obtained by factoring out the upper half-space of $\mathbb{R}^n$ by arithmetic subgroups of generalized…

Analysis of PDEs · Mathematics 2007-05-23 Elizabeth Bulla , Denis Constales , Rolf Soeren Krausshar , John Ryan

We study Dirac operators on resolutions of Riemannian orbifolds by developing a uniform elliptic theory. The key idea is to view orbifolds as conically fibred singular (CFS) spaces and resolve them by gluing asymptotically conical…

Differential Geometry · Mathematics 2025-09-23 Viktor F. Majewski

Let $c:\mathcal{G}\to\R$ be a cocycle on a locally compact Hausdorff groupoid $\mathcal{G}$ with Haar system. Under some mild conditions (satisfied by all integer valued cocycles on \'{e}tale groupoids), $c$ gives rise to an unbounded odd…

K-Theory and Homology · Mathematics 2019-11-28 Bram Mesland

In this article, we consider the manifold learning problem when the data set is invariant under the action of a compact Lie group $K$. Our approach consists in augmenting the data-induced graph Laplacian by integrating over the $K$-orbits…

Machine Learning · Computer Science 2023-04-04 Paulina Hoyos , Joe Kileel

We consider a generalized APS boundary problem for a G-invariant Dirac-type operator, which is not of product type near the boundary. We establish a delocalized version (a so-called Kirillov formula) of the equivariant index theorem for…

Differential Geometry · Mathematics 2017-09-20 Maxim Braverman , Gideon Maschler

In this paper we prove that Dirac operators on non-compact complete orbifolds which are sufficiently regular at infinity, admit a unique extension. Additonally, we prove a generalized orbifold Stokes'/Divergence theorem.

Differential Geometry · Mathematics 2008-09-22 Carla Farsi

We revisit the cohomological index theorem for elliptic elements in the universal enveloping algebra of a Lie groupoid previously proved by the authors. We prove a Thom isomorphism for Lie algebroids which enables us to rewrite the…

Differential Geometry · Mathematics 2013-08-02 M. J. Pflaum , H. Posthuma , X. Tang

Let X be a closed connected contact manifold. On X there is a naturally arising class of hypoelliptic (but not elliptic) operators which are Fredholm. In this paper we solve the index problem for this class of operators. The solution is…

Operator Algebras · Mathematics 2012-12-07 Paul F. Baum , Erik van Erp

It known from the work of Feigin-Tsygan, Weibel and Keller that the cohomology groups of a smooth complex variety X can be recovered from (roughly speaking) its derived category of coherent sheaves. In this paper we show that for a finite…

Algebraic Geometry · Mathematics 2007-05-23 Vladimir Baranovsky

This paper studies the K-homology of a crossed product of a discrete group acting smoothly on a manifold, with a better understanding of the noncommutative geometry of the crossed-product as the primary goal, and the Baum-Connes apparatus…

K-Theory and Homology · Mathematics 2019-06-04 Heath Emerson
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