31/05/2019, 16:00 — 17:00 — Room 6.2.49, Faculty of Sciences of the Universidade de Lisboa
Carlos Santos, CEAFEL
Combinatorial Game Theory: a survey
In the first years of the 20th century the analysis of the game of NIM (by the mathematician Charles L. Bouton) triggered the outburst of a completely new mathematical subject: Combinatorial Game Theory. The aim of this seminar is to give a survey of the development of this mathematical field.
31/05/2019, 17:00 — 18:00 — Room 6.2.49, Faculty of Sciences of the Universidade de Lisboa
Natasha Samko, UiT The Arctic University of Norway
On a class of Integral operators in central generalized Morrey spaces
We find conditions for the boundedness of integral operators $K$ which commute with dilations and rotations, in a central generalized Morrey space. We also show that under the same conditions these operators preserve the subspace of Morrey spaces, known as vanishing Morrey space. In the case of non-negative kernels, we also give necessary conditions for the boundedness. In the case of classical Morrey spaces the obtained sufficient and necessary conditions coincide with each other. In the one-dimensional case we also obtain similar results for global Morrey spaces. In the case of radial kernels we obtain stronger estimates of $Kf$ via spherical means of $f$. We demonstrate the efficiency of the obtained conditions for a variety of examples such as weighted Hardy operators, weighted Hilbert operator, their multi-dimensional versions and others.