CANCELLED: Joint Colloquium: Aidan Sims -- CANCELLED : Graphs, C*-algebras and equilibrium states

This talk has been CANCELLED.


Abstract: The theory of C*-algebras developed in response to the advent of quantum
theory in the early 1900’s, and have since developed into an interesting and active area
of mathematics.  When studying a physical system, we are interested in equilibrium
states of the system – those which remain steady with the passage of time.  In
C*-algebraic models, such equilibrium states are called KMS-states, and are
characterised by a simple-looking algebraic relation.  This relation makes perfectly
good sense even for C*-algebras that are not based on physical systems, and we are
learning that the KMS states of a C*-algebra tend to capture very interesting structural
information.  I will discuss an excellent example of this phenomenon in the context of
the graph C*-algebras that were introduced by Kumjian, Pask, Raeburn and Renault in the
late 1990’s and have since become a major research industry worldwide.  This is joint
work with Astrid an Huef, Marcelo Laca and Iain Raeburn.