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20092026
most citedUnbounded bivariant -theory and correspondences in noncommutative geometry

98 citations · 341 across the 35 of their papers we have counts for

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14 papers · 1 filter

math.KT2026

Bordisms and unbounded -theory

Robin J. Deeley, Magnus Goffeng, Bram Mesland

This monograph studies -theory in its unbounded model. The central object is the -bordism group obtained by imposing the -bordism relation on unbounded -cycles. In…

math.KT2025

The odd spectral localiser via asymptotic morphisms and quasi-projections

Yuezhao Li, Bram Mesland

We describe the index pairing between an odd K-theory class and an odd unbounded Kasparov module by a pair of quasi-projections, supported on a submodule obtained from a finite spe…

math.KT2019★ 7 cited

Homotopy equivalence in unbounded KK-theory

Koen van den Dungen, Bram Mesland

We propose a new notion of unbounded -cycle, mildly generalising unbounded Kasparov modules, for which the direct sum is well-defined. To a pair of -unital …

math.KT2019★ 7 cited

Untwisting twisted spectral triples

Magnus Goffeng, Bram Mesland, Adam Rennie

We examine the index data associated to twisted spectral triples and higher order spectral triples. In particular, we show that a Lipschitz regular twisted spectral triple can alwa…

math.KT2016

Hecke operators in KK-theory and the K-homology of Bianchi groups

Bram Mesland, Mehmet Haluk Sengun

Let be a torsion-free arithmetic group acting on its associated global symmetric space . Assume that is of non-compact type and let act on the geodesic boundary $\pa…

math.KT2016★ 8 cited

Boundaries, spectral triples and K-homology

Iain Forsyth, Magnus Goffeng, Bram Mesland +1

This paper extends the notion of a spectral triple to a relative spectral triple, an unbounded analogue of a relative Fredholm module for an ideal . Examples incl…

math.KT2015★ 25 cited

Shift tail equivalence and an unbounded representative of the Cuntz-Pimsner extension

Magnus Goffeng, Bram Mesland, Adam Rennie

We show how the fine structure in shift-tail equivalence, appearing in the noncommutative geometry of Cuntz-Krieger algebras developed by the first two authors, has an analogue in…

math.KT2015

The bordism group of unbounded KK-cycles

Robin J. Deeley, Magnus Goffeng, Bram Mesland

We consider Hilsum's notion of bordism as an equivalence relation on unbounded -cycles and study the equivalence classes. Upon fixing two -algebras, and a -subalgebra d…

math.KT2014

Spectral triples and finite summability on Cuntz-Krieger algebras

Magnus Goffeng, Bram Mesland

We produce a variety of odd bounded Fredholm modules and odd spectral triples on Cuntz-Krieger algebras by means of realizing these algebras as "the algebra of functions on a non-c…

math.KT2013★ 15 cited

Dense domains, symmetric operators and spectral triples

I. Forsyth, B. Mesland, A. Rennie

This article is about erroneous attempts to weaken the standard definition of unbounded Kasparov module (or spectral triple). We present counterexamples to claims in the literature…

math.KT2013★ 29 cited

Gauge Theory for Spectral Triples and the Unbounded Kasparov Product

Simon Brain, Bram Mesland, Walter D. van Suijlekom

We explore factorizations of noncommutative Riemannian spin geometries over commutative base manifolds in unbounded KK-theory. After setting up the general formalism of unbounded K…

math.KT2013★ 6 cited

Spectral triples and KK-theory: A survey

Bram Mesland

This survey deals with the construction of a category of spectral triples that is compatible with the Kasparov product in -theory. These notes serve as an intuitive guide to th…

math.KT2010★ 6 cited

Groupoid cocycles and K-theory

Bram Mesland

Let be a cocycle on a locally compact Hausdorff groupoid with Haar system. Under some mild conditions (satisfied by all integer valued cocycles o…

math.KT2009★ 98 cited

Unbounded bivariant -theory and correspondences in noncommutative geometry

Bram Mesland

By introducing a notion of smooth connection for unbounded -cycles, we show that the Kasparov product of such cycles can be defined directly, by an algebraic formula. In order…