[Settfa] Tuesday 07/01, Saeed Ghasemi

[kubis at math.cas.cz]

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 Tuesday 7th January, 10:00am 
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 Speaker:Saeed Ghasemi, IM CAS
 Title: Strongly self-absorbing C*-algebras and (weak) Fraisse limits

 Abstract  

 A unital separable C*-algebra (other than the C*-algebra of all complex numbers) is strongly self-absorbing if it is isomorphic to its (minimal) tensor product with itself in a "strong" sense. Strongly self-absorbing C*-algebras play crucial roles in Elliott's classification program of separable nuclear C*-algebras by K-theoretic data, and among them the Jiang-Su algebra is the most notable. In fact, the classification of separable, simple, unital, nuclear C*-algebras that tensorially absorb the Jiang-Su algebra and satisfy the UCT has been the pinnacle of the classification results. In their original paper from 1999, Jiang and Su already proved that the Jiang-Su algebra is strongly self-absorbing. However, their proof is quite complicated and uses heavy tools from classification, such as KK-theory. I will present rather elementary and direct proof for the fact that the Jiang-Su algebra is strongly self-absorbing, which uses a connection between the strongly self-absorbing C
 *-algebras and the (weak) Fraisse limits of categories of C*-algebras that are sufficiently closed under tensor products.

 For more information see the seminar web page at 
 https://calendar.math.cas.cz/set-theory-and-analysis-actual .