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Related papers: The coarse index class with support

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We introduce a slight modification of the usual equivariant $KK$-theory. We use this to give a $KK$-theoretical proof of an equivariant index theorem for Dirac-Schrodinger operators on a non-compact manifold of nowhere positive curvature.…

K-Theory and Homology · Mathematics 2023-06-28 Y. Abdolmaleki , D. Kucerovsky

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 give a simple proof of the cobordism invariance of the index of an elliptic operator. The proof is based on a study of a Witten-type deformation of an extension of the operator to a complete Riemannian manifold. One of the advantages of…

Spectral Theory · Mathematics 2007-05-23 Maxim Braverman

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

The equivariant coarse index is well-understood and widely used for actions by discrete groups. We extend the definition of this index to general locally compact groups. We use a suitable notion of admissible modules over $C^*$-algebras of…

K-Theory and Homology · Mathematics 2022-07-05 Hao Guo , Peter Hochs , Varghese Mathai

We will discuss the equivariant cohomology of a manifold endowed with the action of a Lie group. Localization formulae for equivariant integrals are explained by a vanishing theorem for equivariant cohomology with generalized coefficients.…

Differential Geometry · Mathematics 2007-05-23 Michele Vergne

In this paper we prove a strengthening of a theorem of Chang, Weinberger and Yu on obstructions to the existence of positive scalar curvature metrics on compact manifolds with boundary. They construct a relative index for the Dirac…

K-Theory and Homology · Mathematics 2020-03-18 Thomas Schick , Mehran Seyedhosseini

We study index theory on homogeneous spaces associated to an almost connected Lie group in terms of the topological aspect and the analytic aspect. On the topological aspect, we obtain a topological formula as a result of the Riemann-Roch…

Differential Geometry · Mathematics 2024-01-17 Hang Wang , Zijing Wang

For a $C^{*}$-category with a strict $G$-action we construct examples of equivariant coarse homology theories. To this end we first introduce versions of Roe categories of objects in $C^{*}$-categories which are controlled over bornological…

K-Theory and Homology · Mathematics 2023-06-21 Ulrich Bunke , Alexander Engel

In this paper we solve the general case of the cohomological relative index problem for foliations of non-compact manifolds. In particular, we significantly generalize the groundbreaking results of Gromov and Lawson, [GL83], to Dirac…

Differential Geometry · Mathematics 2024-02-19 Moulay Tahar Benameur , James L. Heitsch

We generalize Roe's Index Theorem for operators of Dirac type on open manifolds to elliptic pseudodifferential operators. To this end we introduce a class of pseudodifferential operators on manifolds of bounded geometry which is more…

Differential Geometry · Mathematics 2014-10-30 Alexander Engel

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

Several formulas for computing coarse indices of twisted Dirac type operators are introduced. One type of such formulas is by composition product in $E$-theory. The other type is by module multiplications in $K$-theory, which also yields an…

K-Theory and Homology · Mathematics 2018-01-03 Christopher Wulff

The Chern classes of a K-theory class which is represented by a vector bundle with connection admit refinements to Cheeger-Simons classes in Deligne cohomology. In the present paper we consider similar refinements in the case where the…

Differential Geometry · Mathematics 2007-05-23 U. Bunke

We define an $S^1$-equivariant index for non-compact symplectic manifolds with Hamiltonian $S^1$-action. We use the perturbation by Dirac-type operator along the $S^1$-orbits. We give a formulation and a proof of quantization conjecture for…

Symplectic Geometry · Mathematics 2018-01-12 Hajime Fujita

A generalization of Callias' index theorem for self adjoint Dirac operators with skew adjoint potentials on asymptotically conic manifolds is presented in which the potential term may have constant rank nullspace at infinity. The index…

Differential Geometry · Mathematics 2018-01-11 Chris Kottke

Coarse geometry, and in particular coarse homotopy theory, has proven to be a powerful tool for approaching problems in geometric group theory and higher index theory. In this paper, we continue to develop theory in this area by proving a…

Geometric Topology · Mathematics 2025-03-03 Thomas Weighill

We consider a complete Riemannian manifold, which consists of a compact interior and one or more $\varphi$-cusps: infinitely long ends of a type that includes cylindrical ends and hyperbolic cusps. Here $\varphi$ is a function of the radial…

Differential Geometry · Mathematics 2023-04-21 Peter Hochs , Hang Wang

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

We show that the computation of the Fredholm index of a fully elliptic pseudodifferential operator on an integrated Lie manifold can be reduced to the computation of the index of a Dirac operator, perturbed by a smoothing operator,…

K-Theory and Homology · Mathematics 2022-04-20 Karsten Bohlen , Jean-Marie Lescure