6th of July | 16h00 (Lisbon time)
Location: Zoom Meeting: https://videoconf-colibri.zoom.us/j/92351703489?pwd=Q245VmlJUitDVS9vZGJkSlJIc3BOUT09
Meeting ID: 923 5170 3489
TITLE :: The Ultrafilter Spectrum
ABSTRACT :: The ultrafilter spectrum for a given cardinal $\kappa$ is the collection of possible sizes of bases for ultrafilters on $\kappa$. The talk will introduce the problem of what one can say about the ultrafilter spectrum and consider older and some more recent results addressing this question. Along the way the current state of set theory will briefly be discussed, with questions about the ultrafilter spectrum serving as illustrations of some strands of interests.
Very little technical set theoretic knowledge should be necessary for the large bulk of the talk.