Arnaud Brothier (UNSW) is speaking in the Algebra Seminar this week. We will go out for lunch after the talk. When: Friday 1 September, 12-1pm Where: Carslaw 173 Title: Classification of representations of the Richard Thompson groups and of the Cuntz algebra Abstract: Vaughan Jones technology permits to lift functors to group actions of fraction groups. This provides new ways to build explicit unitary representations of the Richard Thompson groups F,T,V. I will introduce the so-called Pythagorean C*-algebra and explain how representation of it yield representations of the three Thompson groups and additionally of the Cuntz algebra. I will then explain how to reduce difficult problems concerning irreducibility and unitarily conjugacy of those representations into finite dimensional linear algebra and how beautiful moduli spaces naturally emerge. This is a joint work with Dilshan Wijesena that continues a previous collaboration with Vaughan Jones.