Seminar series
Date
Mon, 04 Nov 2013
14:00
14:00
Location
C6
Speaker
Robert Leek
Organisation
Oxford
This is the first of a series of talks based on Gary
Gruenhage's 'A survey of D-spaces' [1]. A space is D if for every
neighbourhood assignment we can choose a closed discrete set of points
whose assigned neighbourhoods cover the space. The mention of
neighbourhood assignments and a topological notion of smallness (that
is, of being closed and discrete) is peculiar among covering properties.
Despite being introduced in the 70's, we still don't know whether a
Lindelöf or a paracompact space must be D. In this talk, we will examine
some elementary properties of this class via extent and Lindelöf numbers.