Academy of Mathematics and Systems Science, CAS Colloquia & Seminars
Speaker:
Prof. Witold Majdak，AGH University of Science and Technology, Poland
Inviter:
Title:
Weighted shifts on directed semi-trees- an application to creation operators
Time & Venue:
2018.12.13 10:00-11:00 N913
Abstract:
Relating Hilbert space operators to directed graphs can provide some efficient new tools in operator theory. Such an approach has been recently developed by Jablonski, Stochel and Jung who, in order to obtain significantly more information about operators related to graphs, focused their attention on directed trees. They introduced the notion of a weighted shift on a directed tree and effectively investigated properties of a class of such (unbounded) operators. Here we extend this concept to the case of a more general graph which we propose to call a directed semi-tree. The idea of broadening this definition to a larger class of operators was motivated by the fact that the properties of generalized creation operators on Segal–Bargman spaces can be investigated with the help of general properties of weighted shifts on directed semi-trees.