[Settfa] Tuesday 13/02, Saeed Ghasemi

[kubis at math.cas.cz]

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 Tuesday 13th February, 10:00am 
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 Speaker:Saeed Ghasemi, IM CAS
 Title: AF-algebras as Fraisse limits

 Abstract  
It has been shown that the Jiang-Su algebra, all UHF algebras, and the hyperfinite II_1 factor are Fraisse limits of suitable classes of structures. However the class of finite dimensional C*-algebras does not have the amalgamation property (where the maps are *-embeddings) due to obstacles arising from traces of these algebras. Therefore this way not all AF-algebras can be realized as Fraisse limits. I will show that one can obtain the amalgamation property for the category of all finite dimensional subalgebras an AF-algebra where the maps (arrows) are restricted to "inner embeddings" (coming from the unitaries of the algebra), therefore realizing every separable AF-algebra as a Fraisse limit of this category. Also the category of all finite dimensional C*-algebras has the "cofinal amalgamation property".  The talk would include a very basic background on matrics and homomorphisms between them.

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