Data wydarzenia:

Admissibility of Fréchet spaces

Data: wtorek, 16.12.2021, godz. 11.45-13.15

Prelegent: prof. dr hab. Grzegorz Lewicki (Wydział Matematyki i Informatyki UJ)

Abstrakt: 

Let \(E\) be a Hausdorff topological vector space. A subset \(Z\) of \(E\) is said to be admissible if for every compact subset \(K\) of \(Z\) and for every neighborhood \(V\) of zero in \(E\) there exists a continuous mapping \(H:  K \to Z\) such that \(dim(H(K))<+\infty\) and \(x-Hx \in V\) for every \(x \in K\). If \(Z=E\) we say that the space \(E\) is admissible.

This notion plays an important role in the fixed point theory.

The aim of this talk is to show the admissibility of some class of Fréchet spaces. As an application, it will be proved the admissibility of a large class modular spaces equipped with \(F\)-norms  and norms which are certain generalizations of the classical Luxemburg \(F\)-norm and the classical Luxemburg and Orlicz norms in the convex case. Also a linear version of admissibility (so called metric approximation property) for order continuous symmetric spaces will be demonstrated. The talk is based on a joint work with Maciej Ciesielski, Instytut Matematyki Politechniki Poznańskiej.

Miejsce: sala A1-33/34 (RW)