Homotopy in Cuntz classes of Z-stable C*-algebras
Abstract
The Cuntz semigroup of a C*-algebra is an ordered monoid consisting of equivalence classes of positive elements in the stabilization of the algebra. It can be thought of as a generalization of the Murray-von Neumann semigroup, and records substantial information about the structure of the algebra. Here we examine the set of positive elements having a fixed equivalence class in the Cuntz semigroup of a simple, separable, exact and Z-stable C*-algebra and show that this set is path connected when the class is non-compact, i.e., does not correspond to the class of a projection in the C*-algebra. This generalizes a known result from the setting of real rank zero C*-algebras.
Andrew Wiles receives a Basic Science Lifetime Award while Marc Lackenby receives a Frontiers of Science Award for his paper 'A polynomial upper bound on Reidemeister moves'.
The awards will be presented at the 2024 International Congress of Basic Science which takes place in Beijing, China, next week.
Two Oxford Mathematicians, Andrew Wiles and Marc Lackenby, have received Basic Science and Frontiers of Science awards.
Andrew receives a Basic Science Lifetime Award both for his famous proving of Fermat's Last Theorem and its subsequent influence on the development of the field, and for the inspiration he has provided to many aspiring mathematicians.