Local NCG Seminar

This is an informal seminar on noncommutative geometry and related topics organized by the group of master students, PhD students, postdocs and staff working on topics related to noncommutative geometry in Nijmegen and its surroundings. At the same time, it forms a platform where we share with each other our ideas, projects, problems, papers, etc.

Schedule
Reading mini-seminar on “modular theory and entropy”
(as a preparation to this mini-course on modular theory in Utrecht)

Wednesday October 16, 2024 (14:00, HG02.802)More on modular theory and entropy) Selected topics from [Rei, IV, V], [BR2, 6.2.3]
Wednesday October 9, 2024 (14:00, HG02.802)Modular theory II[Rei, III], [BR1, 2.5], [Bla III.4]“time emergence”, Radon-Nykodim theorem for weights
Wednesday October 2, 2024 (14:00, HG02.802)Silvester BorsboomModular theory I[Rei, III], [BR1, 2.5], [Bla III.4] Modular group, Tomita–Takesaki theorem, weights, KMS condition,
Wednesday September 25, 2024 (14:00, HG02.802)Jort de GrootClassification of factors and relative entropy when it seems hopelessBla; III.1, III.3 and III.4] , and 1803.04993(Lattice of) projections, factors, types, dimension, direct integral
Wednesday September 18, 2024 (14:00, HG02.802)Walter van Suijlekom Introduction to entropy [BR1,2]Density matrices, von Neumann entropy, examples, inequalities
Wednesday September 11, 2024 (14:00, HG02.802)Malte LeimbachBasics of von Neumann algebras[Rei, II.3, II.4.b,c], [BR1, 2.4]Operator topologies, bicommutant theorem, density theorems, normal functionals and preduals, W*-algebras, tensor products
References:
[Bla] B. Blackadar, Theory of operator algebras.
[BR1] O. Bratteli and D. W. Robinson, Operator Algebras and Quantum Statistical Mechanics 1.
[BR2] O. Bratteli and D. W. Robinson, Operator Algebras and Quantum Statistical Mechanics 2.
[Rei] B. M. Reible, Monotonicity of the Relative Entropy and the Two-sided Bogoliubov Inequality in von Neumann Algebras, Master’s thesis.
[Tak1] M. Takesaki, Theory of operator algebras I.

Past seminars

Wednesday June 19, 2024 (14:00, HG00.308). Eva-Maria Hekkelman (UNSW). Functional calculus for pseudodifferential operators

Wednesday December 13, 2023 (14:00, HG02.802). Fabian Lux (Yeshiva University). From magnetic skyrmions to noncommutative geometry.

Wednesday December 6, 2023 (14:00, HG02.802). Rodrigo Baptista. Dirac geometry: local structure

Wednesday November 29, 2023 (14:00, HG00.514). Collin Joseph. Topological insulators.

Wednesday November 22, 2023 (14:00, HG00.616). Rodrigo Baptista. Dirac geometry: an introduction

Wednesday November 15, 2023 (14:00, HG02.802). Gaston Nieuviarts (Genova University). Spectral triple-based Noncommutative Gauge Field Theories on AF-algebras:

Wednesday November 8, 2023 (14:00, HG02.802). Shane Farnsworth (The Max Planck Institute for Gravitational Physics). Nonassociative spectral geometry.

Wednesday October 18, 2023 (14:00, HG03.082). Malte Leimbach. A von Neumann algebra approach to quantum metric spaces

Wednesday October 4, 2023 (14:00, HG02.802). Luuk Verhoeven. Random fuzzy geometries and their random matrix models

Wednesday September 27, 2023 (14:00, HG02.802). Luuk Verhoeven. Codimension one immersions as unbounded Kasparov products

Wednesday September 13, 2023 (14:00, HG00.308). Eva-Maria Hekkelman. The joy of MOIs: unbounded multiple operator integrals in NCG

Past reading seminar

In spring 2023 we have been reading the book on higher index theory by Rufus Willett and Guoliang Yu (available online here):

Wednesday 5/7, (14:00, HG02.802)Collin JosephApplication: positive curvatureW&Y 10.2
Wednesday 21/6, (14:00, HG00.308)Malte LeimbachControlled/quantitative K-theory
Wednesday 7/6, (14:00, HG02.508)Yufan GeEquivariant Roe algebras and their relation to group C* algebrasW&Y 5.2-5.3
Wednesday 24/5, (14:00, HG02.508)Aquerman Kuczmenda YanesHigher index via D*-algebrasPapers by Roe
Wednesday 19/4, (14:00, HG02.508)Yuezhao LiLocalization algebrasW&Y 6
Wednesday 5/4, (14:00, HG02.508)Simon Pepin LehalleurThe index as a pairing between K-theory and K-homologyNigel Higson, John Roe. Analytic K-homology Ch. 8.7
Wednesday 29/3, (14:00, HG03.054)Peter HochsElliptic operators and Dirac type operators connections to K-homologyNigel Higson, John Roe. Analytic K-homology Ch. 10
Wednesday 15/3, (14:00, HG03.054, via zoom and in HG02.802)Yufan GeK-homologyNigel Higson, John Roe. Analytic K-homology Ch. 8.1-8.3
Wednesday 1/3, (14:00, HG03.054)Maxime WybouwCoarse geometryNigel Higson, John Roe. Analytic K-homology Ch. 6
/ J. Roe. Lectures on coarse geometry
Wednesday 22/2, (14:00, HG03.054)Malte LeimbachRoe algebrasW&Y: Sect 4.1-4.3, 5.1
Wednesday 15/2, (14:00, HG03.054)Collin JosephK-theory for C*-algebras IIW&Y: Ch2
Wednesday 8/2, (14:00, HG03.054)Aquerman Kuczmenda YanesK-theory for C*-algebras IW&Y: Ch2
Wednesday 1/2, (14:00, HG03.054).Walter van SuijlekomPrelude to higher index theory and planning.W&Y: Ch.3

Past seminars 

Wednesday November 30, 2022 (14:00, room HG02.802). Aquerman Kuczmenda Yanes and Malte Leimbach

Wednesday November 23, 2022 (14:00, room HG02.802). Walter van Suijlekom – Planning for coming months

Wednesday November 9, 2022 (14:00, room HFML0220). Shintaro Nishikawa – K-theory of noncommutative Bernoulli Shifts

Wednesday July 6, 2022 (14:00, room tba). Aquerman Kuczmenda Yanes

Wednesday June 15, 2022 (14:00, room HG02.052). Peter Hochs – Analytic torsion

Wednesday June 8, 2022 (14:00, room HG00.218). Klaas Landsman – canceled

Wednesday May 25, 2022 (14:00, room HG00.218). Mick Gielen – Cyclic cohomology and generalized formal degrees for affine Hecke algebras

Wednesday May 11, 2022 (14:00, room HG00.218). Malte Leimbach –  Spectral truncations of the torus

Wednesday April 13, 2022 (14:00, room HG00.071). Rui Dong – The gauge group and perturbation semigroup of an operator system

Wednesday February 16, 2022 (14:00, room HG00.062). Walter van Suijlekom –  Noncommutative spaces at finite resolution [slides]

Wednesday February 2, 2022 (14:00, room HG00.218). Walter van Suijlekom – Planning for coming semester

Wednesday March 18, 2020 (14:30, room tba). Teun van Nuland – canceled (COVID-19).

Tuesday February 4, 2020 (Geometry Seminar). Saskia Roos (Potsdam)

Tuesday January 28, 2020 (Geometry Seminar). Michael Borinsky (NIKHEF)

Tuesday January 14, 2020  (HG03.085). Rui Dong – Fock space and second quantization.

Tuesday January 7, 2020  (HG02.028). Yari Kraak – Canonical quantization of free fields II.

Tuesday December 10, 2019 (HG02.028). Yari Kraak – Canonical quantization of free fields I.

Tuesday November 26, 2019 (HG02.028). Oscar de Wit – Lagrangian and Hamiltonian formalism: quantum mechanics. 

Tuesday November 12, 2019 (HG02.028). Oscar de Wit – Lagrangian and Hamiltonian formalism: classical mechanics.

Tuesday October 22, 2019. Rui Dong – Spectral action and the second quantization.

Tuesday May 7, 2019. Debashish Singh – Extracting Lorentzian structure from Euclidean fermionic action in noncommutative geometry.

Tuesday April 9, 2019. Ali Chamseddine – Mimetic Gravity and Dark Matter (in HG00.108).

Tuesday April 2, 2019. Ali Chamseddine – Noncommutative Geometry and Particle Physics: Unification (in HG00.622).

Tuesday March 26, 2019. Ali Chamseddine – Noncommutative Geometry and Particle Physics: Introduction (in HG00.622, reception afterwards).

Tuesday March 19, 2019. Luuk Verhoeven – Embedding the circle in the plane in unbounded KK-theory II.

Tuesday March 12, 2019. Luuk Verhoeven – Embedding the circle in the plane in unbounded KK-theory I.

Tuesday February 26, 2019. Walter van Suijlekom – Spectral triples and Gromov-Hausdorff convergence.

Tuesday January 22, 2019. John Barrett – Fuzzy non-commutative geometries.

Tuesday January 15, 2019 Luuk Verhoeven – Embedding the circle in the plane (final presentation MSc thesis, in HG00.068)

Tuesday December 18, 2018. Nesta van der Schaaf – Lie groupoids

Tuesday December 4, 2018. Nesta van der Schaaf – Lie groupoids

Tuesday November 13, 2018. Abel Stern – K-homology

Tuesday November 6, 2018. Abel Stern – K-theory

Tuesday October 30, 2018. Lisa Glaser – Simulating random non-commutative geometries.

Tuesday October 23, 2018. Tey Berendschot – Connes’ distance formula in noncommutative geometry. 

Tuesday October 16, 2018. Luuk Verhoeven – Hearing the shape of a drum.

Tuesday October 2, 2018. Walter van Suijlekom – Dirac operators and spectral triples.