COOKIES: By using this website you agree that we can place Google Analytics Cookies on your device for performance monitoring. |

University of Cambridge > Talks.cam > Isaac Newton Institute Seminar Series > Endomorphisms and automorphisms of the 2-adic ring C*-algebra Q_2

## Endomorphisms and automorphisms of the 2-adic ring C*-algebra Q_2Add to your list(s) Download to your calendar using vCal - Stefano Rossi (Università degli Studi di Roma Tor Vergata)
- Thursday 16 February 2017, 14:00-15:00
- Seminar Room 2, Newton Institute.
If you have a question about this talk, please contact INI IT. OAS - Operator algebras: subfactors and their applications The 2-adic ring C =1. By its very definition it contains a copy of the Cuntz algebra O_2. I'll start by discussing some nice properties of this inclusion, as they came to be pointed out in a recent joint work with V. Aiello and R. Conti. Among other things, the inclusion enjoys a kind of rigidity property, i.e., any endomorphism of the larger that restricts trivially to the smaller must be trivial itself. I'll also say a word or two about the extension problem, which is concerned with extending an endomorphism of O_2 to an endomorphism of Q_2. As a matter of fact, this is not always the case: a wealth of examples of non-extensible endomorphisms (automophisms indeed!) show up as soon as the so-called Bogoljubov automorphisms of O_2 are looked at. Then I'll move on to particular classes of endomorphisms and automorphisms of Q_2, including those fixing the diagonal D_2. Notably, the semigroup of the endomorphisms fixing U turns out to be a maximal abelian group isomorphic with the group of continuous functions from the one-dimensional torus to itself. Such an analysis, though, calls for some knowledge of the inner structure of Q_2. More precisely, it's vital to prove that C(U) is a maximal commutative subalgebra. Time permitting, I'll also try to present forthcoming generalizations to broader classes of C*-algebras, on which we're currently working with N. Stammeier as well.This talk is part of the Isaac Newton Institute Seminar Series series. ## This talk is included in these lists:- All CMS events
- Featured lists
- INI info aggregator
- Isaac Newton Institute Seminar Series
- School of Physical Sciences
- Seminar Room 2, Newton Institute
- bld31
Note that ex-directory lists are not shown. |
## Other listsType the title of a new list here IET Cambridge Network - Lectures Ver Heyden de Lancey Lectures CIKC Talks Sustainability in the Built Environment (GreenBRIDGE) CMS Seminars from business and industry## Other talksThe Anne McLaren Lecture: CRISPR-Cas Gene Editing: Biology, Technology and Ethics CANCELLED-Open tools in Marchantia for plant bioengineering work and as a platform for elucidating morphogenesis The Beginning of Our Universe and what we don't know about Physics Biosensor Technologies (Biacore SPR, Switchsense, Octet) Regulators of Muscle Stem Cell Fate and Function New Insights in Immunopsychiatry (Provisional Title) |