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

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Equivariant cohomology, a captivating fusion of symmetry and abstract mathematics, illuminates the profound role of group actions in shaping geometric structures. At its core lies the Atiyah-Bott Localization Theorem, a mathematical jewel…

Symplectic Geometry · Mathematics 2023-09-21 Catherine C. Notman , Muaadh A. Sanabani

In mid 60s Bott proved that (1) the index theorem for homogeneous, G-invariant, elliptic differential operators acting in the spaces of sections of induced representations of G over G/H reduces to the Weyl character formula and (2) the…

Mathematical Physics · Physics 2007-05-23 Dimitry Leites

Given two metrics of positive scalar curvature metrics on a closed spin manifold, there is a secondary index invariant in real $K$-theory. There exist two definitions of this invariant, one of homotopical flavour, the other one defined by a…

K-Theory and Homology · Mathematics 2016-09-06 Johannes Ebert

We introduce the notion of Atiyah class of a generalized holomorphic vector bundle, which captures the obstruction to the existence of generalized holomorphic connections on the bundle. As in the classical holomorphic case, this Atiyah…

Algebraic Geometry · Mathematics 2023-02-03 Honglei Lang , Xiao Jia , Zhangju Liu

We announce a Godbillon-Vey index formula for longitudinal Dirac operators on a foliated bundle $(X,\F)$ with boundary; in particular, we define a Godbillon-Vey eta invariant on the boundary foliation, that is, a secondary invariant for…

Differential Geometry · Mathematics 2011-02-15 Hitoshi Moriyoshi , Paolo Piazza

We compute the index of the Dirac operator on spin Riemannian manifolds with conical singularities, acting from $L^p(\Sigma^+)$ to $L^q(\Sigma^-)$ with $p,q>1$. When $1+\frac{n}{p}-\frac{n}{q}>0$ we obtain the usual Atiyah-Patodi-Singer…

Differential Geometry · Mathematics 2007-05-23 André Legrand , Sergiu Moroianu

A group G has homological dimension less or equal to 1 if it is locally free. We prove the converse provided that G satisfies the Atiyah Conjecture about L^2-Betti numbers. We also show that a finitely generated elementary amenable group G…

Group Theory · Mathematics 2007-05-23 Peter Kropholler , Peter Linnell , Wolfgang Lueck

The quantization of the superclassical system used in the proof of the index theorem results in a factor of $\hbar^{2}R/8 $ in the Hamiltonian. The path integral expression of the kernel is analyzed up to and including 2-loop order. The…

High Energy Physics - Theory · Physics 2009-10-22 Ali Mostafazadeh

We establish a mod 2 index theorem for real vector bundles over 8k+2 dimensional compact pin$^-$ manifolds. The analytic index is the reduced $\eta$ invariant of (twisted) Dirac operators and the topological index is defined through…

Differential Geometry · Mathematics 2015-08-12 Weiping Zhang

We show that any continuous $\mathbf{C}$-linear Lie algebra splitting of the symbol map from the Atiyah algebra of a vector bundle on a complex manifold is given by a differential operator of order at most the rank of the bundle plus one.…

Algebraic Geometry · Mathematics 2022-11-28 Emile Bouaziz

We study finite dimensional vector spaces over fields of elliptic functions equipped with two commuting aotomorphisms \sigma and \tau induced by isogenies of relatively prime orders. We give a structure theorem for such objects, that…

Number Theory · Mathematics 2021-07-14 Ehud de Shalit

The paper is devoted to the index theory of orbital and transverse elliptic operators on manifolds with a proper Lie group action. It corrects errors of my previous paper (published in JNCG in 2016) on transverse operators and contains new…

K-Theory and Homology · Mathematics 2024-05-28 Gennadi Kasparov

In this paper we explain how Morse theory for the Yang-Mills functional can be used to prove an analogue, for surface groups, of the Atiyah-Segal theorem. Classically, the Atiyah-Segal theorem relates the representation ring R(\Gamma) of a…

Algebraic Topology · Mathematics 2018-05-09 Daniel A. Ramras

We present a new solution to the index problem for hypoelliptic operators in the Heisenberg calculus on contact manifolds, by constructing the appropriate topological K-theory cocycle for such operators. Its Chern character gives a…

Differential Geometry · Mathematics 2010-07-28 Erik van Erp

An expression is found for the $L^2$-index of a Dirac operator coupled to a connection on a $U_n$ vector bundle over $S^1\times{\mathbb R}^3$. Boundary conditions for the connection are given which ensure the coupled Dirac operator is…

Differential Geometry · Mathematics 2007-05-23 Tom M. W. Nye , Michael A. Singer

In this talk, we review the heat kernel approach to the Atiyah-Singer index theorem for Dirac operators on closed manifolds, as well as the Atiyah-Patodi-Singer index theorem for Dirac operators on manifolds with boundary. We also discuss…

Differential Geometry · Mathematics 2016-09-07 Weiping Zhang

We translate the Atiyah's results on classification of vector bundles on elliptic curves to the language of factors of automorphy.

Algebraic Geometry · Mathematics 2010-09-17 Oleksandr Iena

Index theory for Lorentzian Dirac operators is a young subject with significant differences to elliptic index theory. It is based on microlocal analysis instead of standard elliptic theory and one of the main features is that a nontrivial…

Differential Geometry · Mathematics 2025-02-17 Christian Baer , Alexander Strohmaier

Recently, two of the authors of this paper constructed cyclic cocycles on Harish-Chandra's Schwartz algebra of linear reductive Lie groups that detect all information in the $K$-theory of the corresponding group $C^*$-algebra. The main…

Differential Geometry · Mathematics 2021-06-30 Peter Hochs , Yanli Song , Xiang Tang

In this expository article, we consider first order elliptic differential operators acting on smooth vector bundles over compact manifolds, and certain invariants derived from the analysis of these operators, namely the eta invariant} and…

Differential Geometry · Mathematics 2019-08-15 Jochen Brüning , Ken Richardson