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Related papers: The signature package on Witt spaces

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We give a parametrix construction for the signature operator on any compact, oriented, stratified pseudomanifold X which satisfies the Witt condition. This construction is inductive. It is then used to show that the signature operator is…

Differential Geometry · Mathematics 2009-11-04 Pierre Albin , Eric Leichtnam , Rafe Mazzeo , Paolo Piazza

This is a sequel to the paper "The signature package on Witt spaces, I. Index classes" by the same authors. In the first part we investigated, via a parametrix construction, the regularity properties of the signature operator on a…

Differential Geometry · Mathematics 2009-11-09 Pierre Albin , Eric Leichtnam , Rafe Mazzeo , Paolo Piazza

Let M be a compact smoothly stratified pseudomanifold with boundary, satisfying the Witt assumption. In this paper we introduce the de Rham signature and the Hodge signature of M, and prove their equality. Next, building also on recent work…

Differential Geometry · Mathematics 2022-04-28 Paolo Piazza , Boris Vertman

Let G be a compact Lie group and let X be an oriented Witt G-pseudomanifold. Using intersection cohomology it is possible to define Sign(G,X) in R(G), the G-signature of X. Let g be an element in G. Assuming that the inclusion of the fixed…

Differential Geometry · Mathematics 2025-11-27 Markus Banagl , Eric Leichtnam , Paolo Piazza

We revisit the construction of signature classes in C*-algebra K-theory, and develop a variation that allows us to prove equality of signature classes in some situations involving homotopy equivalences of noncompact manifolds that are only…

K-Theory and Homology · Mathematics 2018-10-03 Nigel Higson , Thomas Schick , Zhizhang Xie

Signature plays an important role in geometry and topology. In the space with singularity, Goresky and MacPherson extend the signatures to oriented pseudomanifolds with only even codimensional stratums by using generalized Poincare duality…

K-Theory and Homology · Mathematics 2021-06-25 Mingyu Liu

Witt spaces are pseudomanifolds for which the middle-perversity intersection homology with rational coefficients is self-dual. We give a new construction of the symmetric signature for Witt spaces which is similar in spirit to the…

Algebraic Topology · Mathematics 2013-11-13 Greg Friedman , James McClure

We introduce smooth atlas stratified spaces. We show that this class is closed under cartesian products; consequently, it is possible to define fiber bundles of smooth atlas stratified spaces. We describe the resolution of such a space to a…

Differential Geometry · Mathematics 2025-05-22 Pierre Albin , Markus Banagl , Paolo Piazza

Let $X$ be an algebraic variety over the field of real numbers $\mathbb{R}$. We use the signature of a quadratic form to produce "higher" global signatures relating the derived Witt groups of $X$ to the singular cohomology of the real…

K-Theory and Homology · Mathematics 2015-01-20 Jeremy A. Jacobson

We show that for each discrete group G, the rational assembly map K_*(BG) \otimes Q \to K_*(C*_{max} G) \otimes \Q is injective on classes dual to the subring generated by cohomology classes of degree at most 2 (identifying rational…

K-Theory and Homology · Mathematics 2008-08-21 Bernhard Hanke , Thomas Schick

We prove the Novikov conjecture on oriented Cheeger spaces whose fundamental group satisfies the strong Novikov conjecture. A Cheeger space is a stratified pseudomanifold admitting, through a choice of ideal boundary conditions, an L2-de…

Differential Geometry · Mathematics 2016-04-07 Pierre Albin , Eric Leichtnam , Rafe Mazzeo , Paolo Piazza

Werner Meyer constructed a cocycle in $H^2(Sp(2g, \mathbb{Z}); \mathbb{Z})$ which computes the signature of a closed oriented surface bundle over a surface, with fibre a surface of genus g. By studying properties of this cocycle, he also…

Algebraic Topology · Mathematics 2020-04-15 Dave Benson , Caterina Campagnolo , Andrew Ranicki , Carmen Rovi

John Lott has computed an integer-valued signature for the orbit space of a compact orientable $(4k+1)$ manifold with a semi-free $S^1$-action, which is a homotopy invariant of that space, but he did not construct a Dirac type operator…

Differential Geometry · Mathematics 2018-02-13 Juan Camilo Orduz

Let us consider a compact oriented riemannian manifold M without boundary and of dimension n=4k. The signature of M is defined as the signature of a given quadratic form Q. Two different products could be used to define Q and they render…

Differential Geometry · Mathematics 2015-06-02 Jose Rodriguez

We introduce a class of operators associated with the signature of a smooth path $X$ with values in a $C^{\star}$ algebra $\mathcal{A}$. These operators serve as the basis of Taylor expansions of solutions to controlled differential…

Operator Algebras · Mathematics 2022-12-12 Carlo Bellingeri , Nicolas Gilliers

John Lott defined an integer-valued signature $\sigma_{S^1}(M)$ for the orbit space of a compact orientable manifold with a semi-free $S^1$-action but he did not construct a Dirac-type operator which has this signature as its index. We…

Differential Geometry · Mathematics 2025-04-24 Juan Camilo Orduz

In work of Higson-Roe the fundamental role of the signature as a homotopy and bordism invariant for oriented manifolds is made manifest in how it and related secondary invariants define a natural transformation between the…

K-Theory and Homology · Mathematics 2017-10-04 Pierre Albin , Paolo Piazza

We extend the notion of the symmetric signature $\sigma(\bar{M},r)$ in L^n(R) for a compact n-dimensional manifold M without boundary, a reference map r from M to BG and a homomorphism of rings with involutions from ZG to R to the case with…

Geometric Topology · Mathematics 2007-05-23 Eric Leichtnam , Wolfgang Lueck

In this paper, we obtain two Lichnerowicz type formulas for sub-signature operators. And we give the proof of Kastler-Kalau-Walze type theorems for sub-signature operators on 4-dimensional and 6-dimensional compact manifolds with…

Differential Geometry · Mathematics 2022-02-09 Tong Wu , Sining Wei , Yong Wang

For a normal covering over a closed oriented topological manifold we give a proof of the L2-signature theorem with twisted coefficients, using Lipschitz structures and the Lipschitz signature operator introduced by Teleman. We also prove…

Geometric Topology · Mathematics 2018-11-28 Wolfgang Lueck , Thomas Schick
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