All talks

Past talks

Upcoming talks

Ulrich Bunke

Coarse homotopy theory and K-theory

I will give an overview over basic features of equivariant coarse homotopy theory.  Thereby the emphasis is put on…
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September 30, 2022
14:00
EST
Organized by Americas GNCG Seminar.
Fabio Cipriani

Spectral densities and hypertrace in NCG

We introduce spectral weights ρ(L) of positive, self-adjoint operators L having dis-crete spectrum away from zero. We provide criteria for measurability and…
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May 18, 2022
14:00
CEST
Organized by Europe GNCG Seminar.
Yves Andre

A Remark on the Tate Conjecture

The Tate conjecture has two parts: i) Tate classes are generated by algebraic classes, ii) semisimplicity of Galois representations…
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May 6, 2022
15:00
EST
Organized by Americas GNCG Seminar.
Guo Chuang Thiang

What is a Coarse Index, physically?

The coarse index of J. Roe beautifully expands index theory to noncompact manifolds. It appears abstract at first glance,…
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May 4, 2022
14:00
CEST
Organized by Europe GNCG Seminar.
Sarah Reznikoff

Regular ideals and regular inclusions

We examine the regular ideals of C*-algebras, examining which properties are preserved under quotients by these as well as…
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April 20, 2022
14:00
CEST
Organized by Europe GNCG Seminar.
Rufus Willett

Decomposable C*-algebras and the UCT

A $C^*$-algebra satisfies the UCT if it is K-theoretically the same as a commutative $C^*$-algebra, in some sense.  Whether…
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March 11, 2022
15:00
EST
Organized by Americas GNCG Seminar.
Gui Zhengping

Elliptic trace map on chiral algebras

Trace map on deformation quantized algebra leads to the algebraic index theorem. We investigate a two dimensional chiral analogue…
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March 9, 2022
14:00
CET
Organized by Europe GNCG Seminar.
Shahn Majid

Quantum geodesic flows and curvature

We study geodesics flows on curved quantum Riemannian geometries using a recent formulation in terms of bimodule connections and…
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February 23, 2022
14:00
CET
Organized by Europe GNCG Seminar.
Ivan Todorov

Morita equivalence for operator systems

Morita equivalence, having arisen first in Algebra, has had a continuing impact on non-commutative analysis, after its introduction into…
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January 26, 2022
14:00
CET
Organized by Europe GNCG Seminar.
Gilles Pisier

The lifting property for C*-algebras

We give several characterizations of the lifting property (LP in short) using the maximal tensor product  for $C^*$- algebras. The…
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January 14, 2022
15:00
EST
Organized by Americas GNCG Seminar.
Dustin Clausen

New foundations for functional analysis

I will discuss joint work with Peter Scholze in which we propose replacements for the standard categories of topological…
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November 12, 2021
15:00
EST Toronto
Organized by Americas GNCG Seminar.
Inna Zakharevich

Characteristic polynomials and traces

In this talk we give a description of a lift of the Dennis trace and the characteristic polynomial to…
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October 22, 2021
15:00
EST (Toronto)
Organized by Americas GNCG Seminar.
Benjamin Steinberg

Cartan pairs of algebras

 In the seventies, Feldman and Moore studied Cartan pairs of von Neumann algebras. These pairs consist of an algebra A and a…
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October 8, 2021
15:00
EST
Organized by Americas GNCG Seminar.
Giles Gardam

Kaplansky’s conjectures

The Kadison–Kaplansky conjecture states that the reduced C*-algebra of a torsion-free discrete group has no idempotents other than 0…
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September 17, 2021
15:00
EST (Toronto)
Organized by Americas GNCG Seminar.
Alain Connes

On the Notion of Space

I will analyze two fundamental “spaces” using the paradigms of spectral and of algebraic geometry. The spectral paradigm is…
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September 3, 2021
15:00
EST (Toronto)
Organized by Americas GNCG Seminar.
Lachlan MacDonald

Chern-Weil theory for singular foliations

 Chern-Weil theory describes a procedure for constructing the characteristic classes of a smooth manifold from geometric data (such as…
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June 21, 2021
09:00
UTC
Organized by Asia-Pacific GNCG Seminar.
Chi-Keung Ng

Ortho-sets and Gelfand spectra.

Motivated by quantum states with zero transition probability, we introduce the notion of ortho-set which is a set equipped…
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June 9, 2021
14:00
CEST
Organized by Europe GNCG Seminar.
Alain Connes

Spectral Triples and Zeta-Cycles

This is joint work with C. Consani. When contemplating the low lying zeros of the Riemann zeta function one…
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June 2, 2021
17:15
CEST
Organized by Americas GNCG Seminar.
Romain Tessera

Geometry of lamplighters groups

In a joint work with Anthony Genevois, we classify up to quasi-isometry the class of lamplighter groups over one-ended finitely…
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May 31, 2021
11:00
CEST
Organized by Asia-Pacific GNCG Seminar.
Zhengwei Liu

Quantum Fourier Analysis

Quantum Fourier Analysis is a subject that combines an algebraic Fourier transform (pictorial in the case of subfactor theory) with…
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May 17, 2021
11:00
CEST
Organized by Asia-Pacific GNCG Seminar.
Matthew Kennedy

Noncommutative convexity

Recently, Davidson and I introduced a new framework for noncommutative convexity and noncommutative function theory, along with a corresponding…
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May 5, 2021
16:00
CEST
Organized by Europe GNCG Seminar.
Ieke Moerdijk

An Introduction to Dendroidal Topology

Simplicial sets form a classical and well known tool for modelling topological spaces, and more recently topologically enriched categories…
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April 23, 2021
14:00
EDT
Organized by Americas GNCG Seminar.
Adam Rennie

The constructive Kasparov product

 I will outline efforts to describe the Kasparov product of two unbounded Kasparov modules in terms of another unbounded…
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April 12, 2021
09:00
UTC
Organized by Asia-Pacific GNCG Seminar.
Omar Mohsen

Inhomogeneous pseudo-differential calculus

Using techniques from noncommutative geometry, I will present a very general inhomogeneous pseudo-differential calculus which allows us to obtain…
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April 5, 2021
11:00
CEST
Organized by Asia-Pacific GNCG Seminar.
Dan Voiculescu

Around the Quasicentral Modulus

The quasicentral modulus is a numerical invariant associated with a n-tuple of Hilbert space operators and a normed ideal of…
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March 26, 2021
18:00
UTC
Organized by Americas GNCG Seminar.
Joachim Cuntz

The algebraic approach to KK-theory

Kasparov’s KK-theory which is based on so called Kasparov-modules can be described much more algebraically using universal extensions and classifying maps…
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March 1, 2021
10:00
CET
Organized by Asia-Pacific GNCG Seminar.
Eckhard Meinrenken

Differential Geometry of Weightings

The idea of assigning weights to local coordinate functions appears in many areas of mathematics, such as singularity theory,…
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February 19, 2021
14:00
EST
Organized by Americas GNCG Seminar.
Sergiy Neshveyev

Crystallization of C$^*$-algebras

Given a C$^*$-algebra $A$ with an almost periodic time evolution we define a new C$^*$-algebra $A_c$ whose states parameterize…
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February 16, 2021
15:00
CET
Organized by Europe GNCG Seminar.