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Related papers: Atiyah's $L^2$-Index theorem

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We present an index theorem for certain hypoelliptic differential operators on foliated manifolds. Our proof is a development of Alain Connes tangent groupoid proof of the Atiyah-Singer index theorem. The paper is largely self-contained.

Differential Geometry · Mathematics 2010-02-24 Erik van Erp

We describe how Lie groupoids are used in singular analysis, index theory and non-commutative geometry and give a brief overview of the theory. We also expose groupoid proofs of the Atiyah-Singer index theorem and discuss the Baum-Connes…

Operator Algebras · Mathematics 2017-05-16 Karsten Bohlen

We present the details of our embedding proof of the Atiyah-Patodi-Singer index theorem for Dirac operators on manifolds with boundary.

Differential Geometry · Mathematics 2007-05-23 Xianzhe Dai , Weiping Zhang

Main theorems of the article concern the problem of M. Atiyah on possible values of l^2-Betti numbers. It is shown that all non-negative real numbers are l^2-Betti numbers, and that "many" (for example all non-negative algebraic) real…

Group Theory · Mathematics 2014-12-16 Łukasz Grabowski

This note contains a reformulation of the Hodge index theorem within the framework of Atiyah's $L^2$-index theory. More precisely, given a compact K\"ahler manifold $(M,h)$ of even complex dimension $2m$, we prove that…

Differential Geometry · Mathematics 2018-07-11 Francesco Bei

This is an expository paper which gives a proof of the Atiyah-Singer index theorem for elliptic operators. Specifcally, we compute the geometric K-cycle that corresponds to the analytic K-cycle determined by the operator. This paper and its…

Differential Geometry · Mathematics 2016-11-21 Paul Baum , Erik van Erp

We generalize Illusie's definition of the Atiyah class to complexes with quasi-coherent cohomology on arbitrary algebraic stacks. We show that this gives a global obstruction theory for moduli stacks of complexes in algebraic geometry…

Algebraic Geometry · Mathematics 2024-11-20 Nikolas Kuhn

The Atiyah conjecture for a discrete group G states that the $L^2$-Betti numbers of a finite CW-complex with fundamental group G are integers if G is torsion-free and are rational with denominators determined by the finite subgroups of G in…

Group Theory · Mathematics 2018-11-28 Peter Linnell , Thomas Schick

The Atiyah-Singer index theorem, a landmark achievement of the early 1960s, brings together ideas in analysis, geometry, and topology. We recount some antecedents and motivations; various forms of the theorem; and some of its implications,…

History and Overview · Mathematics 2021-07-09 Daniel S. Freed

In topology there is a theorem of Atiyah, concerning K-theory of classifying space of connected compact Lie group. We consider an algebraic analogue of this theorem. We prove that for a split reductive algebraic group G over a field there…

K-Theory and Homology · Mathematics 2011-11-22 Alisa Knizel , Alexander Neshitov

We give an elementary solution of the index problem for elliptic operators associated with the shift operator along the trajectories of an isometric diffeomorphism of a closed smooth manifold. This solution is based on a reduction (which…

Analysis of PDEs · Mathematics 2011-12-26 A. Savin , E. Schrohe , B. Sternin

We use the symbol calculus for foliations developed in our previous paper to derive a cohomological formula for the Connes-Chern character of the semi-finite spectral triple. The same proof works for the Type I spectral triple of…

Geometric Topology · Mathematics 2018-04-20 Moulay-Tahar Benameur , James L. Heitsch

Given a Galois covering of complete spin manifolds where the base metric has PSC near infinity, we prove that for small enough epsilon > 0, the epsilon spectral projection of the Dirac operator has finite trace in the Atiyah von Neumann…

Operator Algebras · Mathematics 2021-09-15 Moulay-Tahar Benameur

Let $(X_0,\mathcal{F}_0) $ be a compact manifold with boundary endowed with a foliation $\mathcal{F}_0$ which is assumed to be measured and transverse to the boundary. We denote by $\Lambda$ a holonomy invariant transverse measure on…

Differential Geometry · Mathematics 2009-01-06 Paolo Antonini

We establish the basics of the analysis of operators on coverings of manifolds with cylindrical ends with a group of deck transformations $\Gamma$. We prove the $\Gamma$-analogue of the Atiyah-Patodi-Singer formula for Dirac operators on…

Differential Geometry · Mathematics 2008-06-26 Boris Vaillant

Consider a proper, isometric action by a unimodular locally compact group $G$ on a Riemannian manifold $M$ with boundary, such that $M/G$ is compact. Then an equivariant Dirac-type operator $D$ on $M$ under a suitable boundary condition has…

K-Theory and Homology · Mathematics 2020-06-16 Peter Hochs , Bai-Ling Wang , Hang Wang

We study differential operators on complete Riemannian manifolds which act on sections of a bundle of finite type modules over a von Neumann algebra with a trace. We prove a relative index and a Callias-type index theorems for von Neumann…

Differential Geometry · Mathematics 2016-02-23 Maxim Braverman , Simone Cecchini

Let $D$ be a (generalized) Dirac operator on a non-compact complete Riemannian manifold $M$ acted on by a compact Lie group $G$. Let $v:M --> Lie(G)$ be an equivariant map, such that the corresponding vector field on $M$ does not vanish…

Mathematical Physics · Physics 2007-05-23 Maxim Braverman

We establish an $L^2$-Gamma index theorem for the Dirac operator on a globally hyperbolic manifold $M$ with Cauchy hypersurface $\Sigma$ being a Galois covering of a compact smooth manifold with Galois group $\Gamma$. Our argument rewrites…

Differential Geometry · Mathematics 2024-10-10 Orville Damaschke und Boris Vertman

The Atiyah-Singer index theorem on a closed manifold is well understood and appreciated in physics. On the other hand, the Atiyah-Patodi-Singer index, which is an extension to a manifold with boundary, is physicist-unfriendly, in that it is…

High Energy Physics - Lattice · Physics 2021-12-22 Hidenori Fukaya