[Settfa] Tuesday 14/12, Piotr Pikul

[kubis at math.cas.cz]

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 Tuesday 14th December, 10:00am 
 
  Place: IM in konírna 

 
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 Speaker:Piotr Pikul, Jagiellonian University, Krakow, Poland
 Title: Backward extensions of weighted shifts on directed trees

 Abstract  

 Weighted shifts on \ell^2 form a very important class of linear operators. They can be generalised by replacing the linear order of coordinates with a more involved structure of a tree (or even a family of trees). In the study of backward extensions we ask whether a specific operator-theoretic property (In my talk it is subnormality or power hyponormality) of the given weighted shift(s) can be preserved if we extend the underlying structure of the tree(s). "Backward" means, that we add new vertices before the first one (i.e. root of the tree).
 
In the talk I'm going to present results of my recent work, available as a preprint https://arxiv.org/pdf/2109.05970.pdf

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