NedCG seminar 2026

In the fall semester of 2026 Cisca Kalmijn (RU Nijmegen) and I are organizing a reading seminar on K-theory and KK-theory. This is an informal seminar where we set up a collaboration between the noncommutative geometry groups in the Netherlands to study together a topic relevant to the diverse projects of the participants of the seminar. Among other things, we treat K-theory, bounded and unbounded KK-theory, Hilbert C*-modules and K-homology. 

Due to the commute between universities, the sessions consists of three talks and happen approximately monthly. The schedule can be found below.

Schedule (preliminary)

• 29 October 13:00-17:00 (University of Amsterdam, room SP G2.13)

  • Talk 1: Introduction (speaker: Matt Verhoeven, Leiden)

  • Talk 2: Hilbert C*-modules (speaker: Matt Verhoeven, Leiden)

  • Talk 3: K-theory: K_0 basics and examples (speaker: Finn Rijk, UvA)

• 26 November 13:00-16:30 (Leiden University, room Gorleaus BW 0.32)

  • Talk 1: K-theory: K_0 and K_1

  • Talk 2: K-theory: Bott periodicity and Toeplitz extension

  • Talk 3: K-theory: Epilogue

• 10 December 13:00-17:00 (Radboud University Nijmegen, room TBA)

  • Talk 1: KK-theory: Kasparov's picture (speaker: Eline de Jager/Lorenzo Gianfrenceschi, RU)

  • Talk 2: KK-theory: Cuntz' picture and functoriality (speaker: Eline de Jager/Lorenzo Gianfrenceschi, RU)

  • Talk 3: KK-theory: Properties and examples (speaker: Eline de Jager/Lorenzo Gianfrenceschi, RU)

• Topics for later sessions:

  • Unbounded KK-theory

  • Crossed products and equivariance

  • Research talks

Main sources:

• Blackadar, K-theory for operator algebras

• Wegge-Olsen, K-theory and C*-algebras

• Jensen-Thomesen, Elements of KK-theory