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Related papers: An index theorem for higher orbital integrals

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Let G be a connected real reductive group. Orbit integrals define traces on the group algebra of G. We introduce a construction of higher orbit integrals in the direction of higher cyclic cocycles on the Harish-Chandra Schwartz algebra of…

K-Theory and Homology · Mathematics 2019-11-11 Yanli Song , Xiang Tang

In this article, we survey the recent constructions of cyclic cocycles on the Harish-Chandra Schwartz algebra of a connected real reductive Lie group $G$ and their applications to higher index theory for proper cocompact $G$-actions.

K-Theory and Homology · Mathematics 2023-09-07 Paolo Piazza , Xiang Tang

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

Given a proper, cocompact action of a Lie groupoid, we define a higher index pairing between invariant elliptic differential operators and smooth groupoid cohomology classes. We prove a cohomological index formula for this pairing by…

Differential Geometry · Mathematics 2014-06-06 M. J. Pflaum , H. Posthuma , X. Tang

For a proper, cocompact action by a locally compact group of the form $H \times G$, with $H$ compact, we define an $H \times G$-equivariant index of $H$-transversally elliptic operators, which takes values in $KK_*(C^*H, C^*G)$. This…

K-Theory and Homology · Mathematics 2020-06-24 Peter Hochs , Hang Wang

For a Lie groupoid there is an analytic index morphism which takes values in the $K-$theory of the $C^*$-algebra associated to the groupoid. This is a good invariant but extracting numerical invariants from it, with the existent tools, is…

K-Theory and Homology · Mathematics 2007-05-23 Paulo Carrillo Rouse

We prove index formulas for elliptic operators acting between sections of C*-vector bundles on a closed manifold. The formulas involve Karoubi's Chern character from K-theory of a C*-algebra to de Rham homology of smooth subalgebras. We…

K-Theory and Homology · Mathematics 2009-01-03 Charlotte Wahl

We prove the index theorem for elliptic operators acting on sections of bundles where fiber is equal to a projective module over a C*-algebra, in the situation of action of a compact Lie group on this algebra as well as on the total space…

Operator Algebras · Mathematics 2007-05-23 Evgenij V. Troitsky

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

We compute explicitly the K-groups of some boundary groupoid C*-algebras with exponential isotropy subgroups. Then we derive index formulas that computes the K-theoretic and Fredholm indexes of elliptic (respectively totally elliptic)…

K-Theory and Homology · Mathematics 2018-04-30 Bing Kwan So

We consider a invariant Dirac operator D on a manifold with a proper and cocompact action of a discrete group G. It gives rise to an equivariant K-homology class [D]. We show how the index of the induced orbifold Dirac operator can be…

K-Theory and Homology · Mathematics 2007-05-23 Ulrich Bunke

We study multivariate generalisations of the classical Wiener--Hopf algebra, which is the C$^*$-algebra generated by the Wiener--Hopf operators, given by the convolutions restricted to convex cones. By the work of Muhly and Renault, this…

Operator Algebras · Mathematics 2009-11-05 Alexander Alldridge , Troels Roussau Johansen

We give a uniform construction of the higher indices of elliptic operators associated to Alexander-Spanier cocycles of either parity in terms of a pairing a la Connes between the K-theory and the cyclic cohomology of the algebra of complete…

K-Theory and Homology · Mathematics 2018-09-26 Alexander Gorokhovsky , Henri Moscovici

Let $A$ be a graded C*-algebra. We characterize Kasparov's K-theory group $\hat{K}_0(A)$ in terms of graded *-homomorphisms by proving a general converse to the functional calculus theorem for self-adjoint regular operators on graded…

Operator Algebras · Mathematics 2016-09-07 Jody Trout

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

For any Lie groupoid we construct an analytic index morphism taking values in a modified $K-theory$ group which involves the convolution algebra of compactly supported smooth functions over the groupoid. The construction is performed by…

K-Theory and Homology · Mathematics 2008-03-17 Paulo Carrillo Rouse

Let $G$ be a connected, real semisimple Lie group. Let $K<G$ be maximal compact, and let $\Gamma < G$ be discrete and such that $\Gamma \backslash G$ has finite volume. If the real rank of $G$ is $1$ and $\Gamma$ is torsion-free, then…

K-Theory and Homology · Mathematics 2025-05-06 Hao Guo , Peter Hochs , Hang Wang

Index theory revealed its outstanding role in the study of periodic orbits of Hamiltonian systems and the dynamical consequences of this theory are enormous. Although the index theory in the periodic case is well-established, very few…

Dynamical Systems · Mathematics 2017-03-14 Xijun Hu , Alessandro Portaluri

In this article we survey some of the recent goings-on in the classification programme of C$^*$-algebras, following the interesting link found between the Cuntz semigroup and the classical Elliott invariant and the fact that the Elliott…

Operator Algebras · Mathematics 2009-02-20 Pere Ara , Francesc Perera , Andrew S. Toms

Using the concept of a twisted trace density on a cyclic groupoid, a trace is constructed on a formal deformation quantization of a symplectic orbifold. An algebraic index theorem for orbifolds follows as a consequence of a local…

K-Theory and Homology · Mathematics 2007-05-23 Markus J. Pflaum , Hessel Posthuma , Xiang Tang
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