Dorothea Bahns

### Equilibrium states for the massive Sine-Gordon Theory in the Lorentzian signature

In my talk I will report on recent joint work with Kasia Rejzner and Nicola Pinamonti on the massive…
June 23, 2021
14:00
CEST
Organized by Europe 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…
June 21, 2021
09:00
UTC
Organized by Asia-Pacific GNCG Seminar.
David Kyed

### The Podleś spheres converge to the sphere

The Podleś spheres, which are q-deformed analogues of the 2-sphere, are among the most classical objects in non-commutative geometry, but…
June 16, 2021
14:00
CEST
Organized by Europe GNCG Seminar.
Valerio Proietti

### Noncommutative algebraic topology and hyperbolic dynamics

The hyperbolic sets of Smale’s Axiom A systems have been defined in the topological setting by Ruelle. We will…
June 14, 2021
09:00
UTC
Organized by Asia-Pacific GNCG Seminar.
Chi-Keung Ng

### Dual spaces of operator systems

June 9, 2021
14:00
CEST
Organized by Europe GNCG Seminar.
Nigel Higson

### The Oka Principle and a K-theoretic Perspective on the Langlands Classification

June 9, 2021
15:15
UTC
Organized by Americas GNCG Seminar.
Nick Wright

### K-theory for Exceptional Extended Affine Weyl Groups

Affine Weyl groups are a class of groups for which the group C^*-algebra can in principle be understood directly. …
June 7, 2021
09:00
UTC
Organized by Asia-Pacific GNCG Seminar.

### Nonproduct geometries: the Standard Model and gravity

Models of noncommutative geometry that are beyond the usual almost-commutative framework that assumes product geometries, may lead to interesting…
June 2, 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…
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…
May 31, 2021
11:00
CEST
Organized by Asia-Pacific GNCG Seminar.
Raimar Wulkenhaar

### Topological recursion of scalar fields in noncommutative geometry

Finite-dimensional approximations of noncommutative quantum field theories are matrix models. They often show rich mathematical structures: many of them…
May 26, 2021
14:00
CEST
Organized by Europe GNCG Seminar.
Steve Rosenberg

### Wodzicki characteristic classes and diffeomorphism groups

The Wodzicki residue can be used to build Chern classes and Chern-Simons classes for infinite dimensional bundles with pseudodifferential…
May 24, 2021
11:00
CEST
Organized by Asia-Pacific GNCG Seminar.
Koen van den Dungen

### Localisations and the Kasparov product in unbounded KK-theory

A well-known theorem by Connes and Skandalis provides sufficient conditions for finding the Kasparov product of two (bounded) Kasparov…
May 19, 2021
14:00
CEST
Organized by Europe 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…
May 17, 2021
11:00
CEST
Organized by Asia-Pacific GNCG Seminar.
Nikita Sopenko

### Invertible states of quantum lattice spin systems and their invariants

Recently methods of quantum statistical mechanics have been fruitfully applied to the study of phases of quantum lattice systems…
May 14, 2021
14:00
EDT
Organized by Americas GNCG Seminar.
Karen Strung

### Positive Line Bundles Over the Irreducible Quantum Flag Manifolds

Noncommutative Kähler structures were recently introduced by Ó Buachalla as a framework for studying noncommutative Kähler geometry on quantum…
May 12, 2021
14:00
CEST
Organized by Europe GNCG Seminar.
Edward McDonald

### Semiclassical Weyl law and exact spectral asymptotics in noncommutative geometry

I discuss how a Tauberian theorem for singular values of noncommuting operators allows us to prove Weyl asymptotic formulas…
May 10, 2021
09:00
UTC
Organized by Asia-Pacific GNCG Seminar.
Zhizhang Xie

### A relative index theorem for incomplete manifolds and Gromov’s conjectures on positive scalar curvature

In this talk, I will speak about my recent work on a relative index theorem for incomplete manifolds. As…
May 7, 2021
14:00
EDT
Organized by Americas 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…
May 5, 2021
16:00
CEST
Organized by Europe GNCG Seminar.
Anna Skripka

### Approximation of functions of unbounded operators

We will discuss recent advancements in approximation of functional calculus arising in problems of mathematical physics and noncommutative geometry….
April 30, 2021
14:00
EDT
Organized by Americas GNCG Seminar.

### Translation invariant noncommutative Dirichlet forms

We shall discuss a class of noncommutative probabilistic evolutions, understood as Markov semigroups acting on von Neumann algebras and…
April 28, 2021
14:00
CEST
Organized by Europe GNCG Seminar.
Shin-ichi Oguni

### A coarse Cartan-Hadamard theorem with application to the coarse Baum-Connes conjecture

We show a coarse version of the Cartan-Hadamard theorem,which states that proper coarsely convex spaces are coarsely homotopyequivalent to…
April 26, 2021
11:00
CEST
Organized by Asia-Pacific 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…
April 23, 2021
14:00
EDT
Organized by Americas GNCG Seminar.
Sanaz Pooya

### Higher Kazhdan projections, L²-Betti numbers, and the Coarse Baum-Connes conjecture

The Baum-Connes conjecture, if it holds for a certain group, provides topological tools to compute the K-theory of its…
April 21, 2021
14:00
CET
Organized by Europe GNCG Seminar.
Wilhelm Winter

### Completely positive approximations revisited

I will try to put into context several well-known and one or two new facts around completely positive approximations of…
April 19, 2021
09:00
UTC
Organized by Asia-Pacific GNCG Seminar.
Yang Liu

### Hypergeometric Functions and Heat Coefficients on Noncommutative Tori

As the counterpart of conformal geometry, modular geometry  on noncommutative manifolds explores the basic notions such as metric and curvature…
April 16, 2021
14:00
EDT
Organized by Americas GNCG Seminar.
Paulo Carrillo Rouse

### Chern assembly map for discrete groups and index theory

In this talk, I will report on joint work with B.L. WANG (ANU Canberra) et H. WANG (ECNU Shanghai). Given a discrete group $$G$$, I…
April 14, 2021
14:00
CEST
Organized by Europe GNCG Seminar.

### The constructive Kasparov product

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

### A noncommutative extension of Mahler’s interpolation theorem

Abstract. I will report on a result recently obtained with Christophe Reutenauer.Let p be a prime number. Mahler’s theorem…
April 9, 2021
14:00
EDT
Organized by Americas GNCG Seminar.
Francesco Fidaleo

### Modular Spectral Triples arising from type III representations of the noncommutative torus

We discuss the explicit construction of non type $$II_1$$ representations and relative modular spectral triples of the noncommutative 2-torus…
April 7, 2021
14:00
CET
Organized by Europe 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…
April 5, 2021
11:00
CEST
Organized by Asia-Pacific GNCG Seminar.
Henrique Bursztyn

### Relating Morita equivalence in algebra and geometry via deformation quantization.

The notion of Morita equivalence, native to ring theory, plays an important role in noncommutative geometry and has a…
April 2, 2021
14:00
EDT
Organized by Americas GNCG Seminar.

### Twisted real structures for spectral triples

Twisted real structures were introduced in 2016 as a generalisation of real structures for spectral triples which permit the…
March 31, 2021
14:00
CET
Organized by Europe GNCG Seminar.
Benoît Collins

### Matrix models for non-commutative rational functions

We will report on arXiv:2103.05962, written in collaboration with Tobias Mai, Akihiro Miyagawa, Felix Parraud and Sheng Yin. Random matrix…
March 29, 2021
18:00
JST
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…
March 26, 2021
18:00
UTC
Organized by Americas GNCG Seminar.
Hermann Schulz-Baldes

### Computational $$K$$-theory via the spectral localizer

Parings of $$K$$-theory with Fredholm modules given by Dirac operators can be computed numerically as the half-signature of a…
March 24, 2021
14:00
CET
Organized by Europe GNCG Seminar.
Stefaan Vaes

### W*-rigidity paradigms for embeddings of II_1 factors

I will report on a recent joint work with Sorin Popa in which we undertake a systematic study of…
March 22, 2021
10:00
CET
Organized by Asia-Pacific GNCG Seminar.
Pere Ara

### Crossed products and the Atiyah problem

It was shown by Austin in 2013 that the question by Atiyah about the rationality of $\ell^2$-Betti numbers has…
March 19, 2021
14:00
EDT
Organized by Americas GNCG Seminar.
Catherine Meusburger

### Turaev-Viro State sum models with defects

We explain how to construct a Traev-Viro style state sum model with defects, where defect planes are labelled by…
March 17, 2021
14:00
CET
Organized by Europe GNCG Seminar.
Hao Guo

### Scalar curvature, band width, and quantitative K-theory

I will discuss two connections between quantitative operator K-theory and scalar curvature, arising from recent work with Zhizhang Xie…
March 15, 2021
20:00
GMT+11
Organized by Asia-Pacific GNCG Seminar.
Asghar Ghorbanpour

### Scalar curvature of functional metrics on noncommutative tori

In recent years, the investigation of geometries of noncommutative tori has attracted attention from both mathematics and physics. In…
March 12, 2021
14:00
EST
Organized by Americas GNCG Seminar.
Paolo Piazza

### Surgery sequences and higher invariants of Dirac operators

The analysis of the signature operator and of the spin-Dirac operator on a $$\Gamma$$-Galois covering of a smooth compact…
March 10, 2021
14:00
CET
Organized by Europe GNCG Seminar.
Shilin Yu

### Deformation quantization of coadjoint orbits

The “coadjoint orbit method” philosophy of Kirillov and Kostant suggests that there is a close connection between the unitary…
March 8, 2021
17:00
GMT+8
Organized by Asia-Pacific GNCG Seminar.
Claire Debord

### Cyclic subsets, groupoids and VB-groupoids

In this talk,  after recalling basic facts on groupoids, we will see that the structure of a groupoid G…
March 5, 2021
14:00
EST
Organized by Americas GNCG Seminar.
Kristin Courtney

### Generalized inductive limits with asymptotically order zero maps

In the 1990s, Blackadar and Kirchberg introduced NF algebras, which arise as limits of inductive systems where the connecting…
March 2, 2021
15:00
CET
Organized by Europe 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…
March 1, 2021
10:00
CET
Organized by Asia-Pacific GNCG Seminar.
Alcides Buss

### Amenable actions of groups on C*-algebras

In this lecture I will explain recent developments in the theory of amenability for actions of groups on C*-algebras…
February 26, 2021
14:00
EST
Organized by Americas GNCG Seminar.
Xiang Tang

### Cyclic Cocycles for Proper Lie Group Actions

In this talk, we will report our exploration of cyclic cohomology of the Harish-Chandra Schwartz algebra of a connected…
February 23, 2021
15:00
CET
Organized by Europe 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,…
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…
February 16, 2021
15:00
CET
Organized by Europe GNCG Seminar.
Henry Yuen

### Testing low-degree polynomials in the noncommutative setting

In low-degree testing the following question is considered: given a multivariate function over a finite field, if a sufficiently…
February 12, 2021
14:00
EST
Organized by Americas GNCG Seminar.
Sylvie Paycha

### A Galois group on meromorphic germs and locality evaluators

Meromorphic germs (say at zero) in several variables with linear poles naturally arise in the context of renormalisation, which…
February 9, 2021
15:00
CET
Organized by Europe GNCG Seminar.
Jens Hemelaer

### Toposes in arithmetic noncommutative geometry

We give an introduction to topos theory from a geometric point of view, focusing on toposes that arise from…
February 5, 2021
14:00
EST
Organized by Americas GNCG Seminar.
Lisa Glaser

### Truncated spectral triples on the computer

When describing a Riemannian geometry as a spectral triple, the algebra of functions on the geometry is infinite. But…
February 2, 2021
15:00
CET
Organized by Europe GNCG Seminar.
Pierre Albin

### The sub-Riemannian limit of a contact manifold

Contact manifolds, which arise naturally in mechanics, dynamics, and geometry, carry natural Riemannian and sub-Riemannian structures and it was…
January 29, 2021
14:00
EST
Organized by Americas GNCG Seminar.
Andreas Thom

### Asymptotics of Cheeger constants and unitarisability of groups

Given a group Γ, we establish a connection between the unitarisability of its uniformly bounded representations and the asymptotic behaviour…
January 26, 2021
16:00
CET
Organized by Europe GNCG Seminar.
Emil Prodan

### Non-Commutative Geometry and Materials Science

Starting with the pioneering works of Jean Bellissard in the 1980’s,Non-Commutative Geometry has emerged as one of sharpest tools…
January 22, 2021
14:00
EST
Organized by Americas GNCG Seminar.
Francesco D’Andrea

### The K-theory of quantized CW-complexes

If a quantum space X can be obtained by “gluing” two subspaces Y and Z, there is a Mayer-Vietoris…
January 19, 2021
15:00
CET
Organized by Europe GNCG Seminar.
Elmar Schrohe

### Index Theory for Fourier Integral Operators and the Connes-Moscovici Local Index Formulae

The index theory for operator algebras generated by pseudodifferential operators and Fourier integral operators, more specifically Lie groups of…
January 12, 2021
15:00
CET
Organized by Europe GNCG Seminar.
Zhaoting Wei

### Determinant line bundles and cohesive modules

December 16, 2020
19:00
UTC
Organized by Americas GNCG Seminar.
Iakovos Androulidakis

### The Heisenberg calculus of singular Lie filtration

December 9, 2020
19:00
UTC
Organized by Americas GNCG Seminar.
Sheagan John

### Secondary higher invariants, and cyclic cohomology for groups of polynomial growth

December 2, 2020
19:00
UTC
Organized by Americas GNCG Seminar.
Francesca Arici

### SU(2)-symmetries and exact sequences of C*-algebras through subproduct systems

November 17, 2020
00:00
CET
Organized by Europe GNCG Seminar.
Nigel Higson

### The Oka principle and Novodvorskii’s theorem

November 11, 2020
19:00
UTC
Organized by Americas GNCG Seminar.
Ralf Meyer

### On the classification of group actions on C*-algebras up to equivariant KK-equivalence

November 10, 2020
15:00
CEST
Organized by Europe GNCG Seminar.
Rudy Rodsphon

### A KK-theoretical perspective on quantization commutes with reduction

November 4, 2020
19:00
UTC
Organized by Americas GNCG Seminar.
Christiaan van de Ven

### Asymptotic equivalence of two strict deformation quantizations and applications to the classical limit

November 3, 2020
15:00
CEST
Organized by Americas GNCG Seminar.
Matthew Lorentz

### The Hochschild cohomology of uniform Roe algebras

October 28, 2020
19:00
UTC
Organized by Americas GNCG Seminar.
Boris Tsygan

### Some remarks on operations on Hochschild and cyclic complexes

October 27, 2020
15:00
CEST
Organized by Europe GNCG Seminar.
Jonathan Block

### Singular foliations and characteristic classes

October 21, 2020
19:00
UTC
Organized by Americas GNCG Seminar.
Henri Moscovici

### Differentiable Characters and Hopf Cyclic Cohomology

October 20, 2020
15:00
CEST
Organized by Europe GNCG Seminar.
Paolo Piazza

### Higher genera and C*-indices on G-proper manifolds

October 14, 2020
18:00
UTC
Organized by Americas GNCG Seminar.

### Equilibrium states for C*-algebras of right LCM monoids.

October 13, 2020
15:00
CEST
Organized by Europe GNCG Seminar.
Bogdan Nica

### On norms of averaging operators on geometric groups

October 7, 2020
19:00
UTC
Organized by Americas GNCG Seminar.
Nigel Higson

### A counterfactual history of the hypoelliptic Laplacian

October 6, 2020
15:00
CEST
Organized by Europe GNCG Seminar.
Simone Cecchini

### A long neck principle for Riemannian spin manifolds with positive scalar curvature

September 30, 2020
19:00
UTC
Organized by Americas GNCG Seminar.
Makoto Yamashita

### Homology and K-theory of torsion free ample groupoids and Smale spaces

September 29, 2020
15:00
CEST
Organized by Europe GNCG Seminar.
Rudolf Zeidler

### Scalar curvature comparison via the Dirac operator

September 23, 2020
19:00
UTC
Organized by Americas GNCG Seminar.
Alain Connes

### Quasi-inner functions and quantized calculus

September 22, 2020
15:00
CEST
Organized by Europe GNCG Seminar.
Kristin Courtney

### C*-structure on images of completely positive order zero maps

September 16, 2020
19:00
UTC
Organized by Americas GNCG Seminar.
Anna Duwenig

### Non-commutative Poincaré duality of the irrational rotation algebra

September 9, 2020
19:00
UTC
Organized by Americas GNCG Seminar.
Bruno de Mendonca Braga

### Coarse equivalences of metric spaces and out automorphisms of Roe algebras

September 2, 2020
19:00
UTC
Organized by Americas GNCG Seminar.
Giovanni Landi

### Solutions to the quantum YB equation and related deformations

August 26, 2020
19:00
UTC
Organized by Americas GNCG Seminar.
Yi Wang

### The Helton-Howe trace formula on submodules

August 19, 2020
19:00
UTC
Organized by Americas GNCG Seminar.
Jonathan Belcher

### Bridge cohomology-a generalization of Hochschild and cyclic cohomologies

August 12, 2020
19:00
UTC
Organized by Americas GNCG Seminar.
Jintao Deng

### The Novikov conjecture and group extensions

August 5, 2020
19:00
UTC
Organized by Americas GNCG Seminar.
Markus Pflaum

### Localization in Hochschild homology and an application to the Hochschild homology of convolution algebras of circle actions

July 29, 2020
19:00
UTC
Organized by Americas GNCG Seminar.
Raphael Ponge

### Analysis on curved noncommutative tori

July 22, 2020
19:00
UTC
Organized by Americas GNCG Seminar.
Masoud Khalkhali

### Newton divided differences, higher curved quantum tori, and scalar curvature

July 15, 2020
18:00
UTC
Organized by Americas GNCG Seminar.
Aurelien Sagnier

### Towards arithmetic sites at some places

July 8, 2020
19:00
UTC
Organized by Americas GNCG Seminar.
Carla Farsi

### Proper Lie Groupoids and their structures

June 24, 2020
19:00
UTC
Organized by Americas GNCG Seminar.
Shintaro Nishikawa

### Sp(n,1) admits a proper 1-cocycle for a uniformly bounded representation

June 17, 2020
19:00
UTC
Organized by Americas GNCG Seminar.
Jianchao Wu

### The Novikov conjecture and C*-algebras of infinite dimensional nonpositively curved spaces

June 10, 2020
19:00
UTC
Organized by Americas GNCG Seminar.
Paolo Antonini

### The Baum-Connes conjecture localized at the unit element of a discrete group

June 3, 2020
19:00
UTC
Organized by Americas GNCG Seminar.
Zhizhang Xie

### Approximations of delocalized eta invariants by their finite analogues

May 27, 2020
19:00
UTC
Organized by Americas GNCG Seminar.
Rufus Willett

### Approximate ideal structures and K-theory

May 20, 2020
19:00
UTC
Organized by Americas GNCG Seminar.
Robin Deeley

### The K-theory of the stable algebra and stable Ruelle algebra of a Wieler solenoid

May 13, 2020
19:00
UTC
Organized by Americas GNCG Seminar.
Yanli Song

### Higher index theorem for proper actions of Lie groups

May 6, 2020
18:00
UTC
Organized by Americas GNCG Seminar.
Boris Tsygan

### Rigidity, the Goodwillie regulator, and the Gauss-Manin connection over p-adic integers

April 29, 2020
19:00
UTC
Organized by Americas GNCG Seminar.
Jonathan Rosenberg

### Positive scalar curvature on a class of spin pseudomanifolds

April 22, 2020
19:00
UTC
Organized by Americas GNCG Seminar.
Dorothea Bahns
Georg-August-Universität Göttingen

### Equilibrium states for the massive Sine-Gordon Theory in the Lorentzian signature

June 23, 2021
14:00
(CEST)
Lachlan MacDonald

### Chern-Weil theory for singular foliations

June 21, 2021
09:00
(UTC)
David Kyed
Syddansk Universitet

### The Podleś spheres converge to the sphere

June 16, 2021
14:00
(CEST)
Valerio Proietti
East China Normal University

### Noncommutative algebraic topology and hyperbolic dynamics

June 14, 2021
09:00
(UTC)
Chi-Keung Ng
Nankai University

### Dual spaces of operator systems

June 9, 2021
14:00
(CEST)
Nigel Higson
Penn State University

### The Oka Principle and a K-theoretic Perspective on the Langlands Classification

June 9, 2021
15:15
(UTC)
Nick Wright
the University of Southampton

### K-theory for Exceptional Extended Affine Weyl Groups

June 7, 2021
09:00
(UTC)
Jagiellonian University, Krakow/ Indiana University Bloomington

### Nonproduct geometries: the Standard Model and gravity

June 2, 2021
14:00
(CEST)
Alain Connes
IHÉS/Collège de France

### Spectral Triples and Zeta-Cycles

June 2, 2021
17:15
(CEST)
Romain Tessera
Institut de Mathématiques de Jussieu – Paris Rive Gauche

### Geometry of lamplighters groups

May 31, 2021
11:00
(CEST)
Raimar Wulkenhaar
Westfälische Wilhelms-Universität Münster

### Topological recursion of scalar fields in noncommutative geometry

May 26, 2021
14:00
(CEST)
Steve Rosenberg
Boston University

### Wodzicki characteristic classes and diffeomorphism groups

May 24, 2021
11:00
(CEST)
Koen van den Dungen
Universität Bonn

### Localisations and the Kasparov product in unbounded KK-theory

May 19, 2021
14:00
(CEST)
Zhengwei Liu
Tsinghua University

May 17, 2021
11:00
(CEST)
Nikita Sopenko
Caltech

### Invertible states of quantum lattice spin systems and their invariants

May 14, 2021
14:00
(EDT)
Karen Strung
Institute of Mathematics, Czech Academy of Sciences

### Positive Line Bundles Over the Irreducible Quantum Flag Manifolds

May 12, 2021
14:00
(CEST)
Edward McDonald
University of New South Wales, Australia

### Semiclassical Weyl law and exact spectral asymptotics in noncommutative geometry

May 10, 2021
09:00
(UTC)
Zhizhang Xie
Texas A&M University

### A relative index theorem for incomplete manifolds and Gromov’s conjectures on positive scalar curvature

May 7, 2021
14:00
(EDT)
Matthew Kennedy
University of Waterloo

### Noncommutative convexity

May 5, 2021
16:00
(CEST)
Anna Skripka
University of New Mexico

April 30, 2021