Forthcoming events in this series


Wed, 27 Feb 2008
15:00
L3

TBA

TBA
Wed, 13 Feb 2008
15:00
L3

TBA

TBA
Wed, 06 Feb 2008
15:00
L3

TBA

TBA
Thu, 10 Jan 2008
10:30
L3

Profinite completion and MacNeille completion can coincide on modal algebras

Jacob Vosmaer
(Amsterdam)
Abstract

We show that the profinite completion (a universal algebraic

construction) and the MacNeille completion (an order-theoretic

construction) of a modal algebra $A$ coincide, precisely when the congruences of finite index of $A$ correspond to principal order filters. Examples of such modal algebras are the free K4-algebra and the free PDL-algebra on finitely many generators.

Mon, 01 Oct 2007
16:00
L3

Some notions of smallness in Polish groups

Udayan Darji
(University of Louisville)
Abstract
In this talk we discusss some notions of small sets in Polish groups. We give some examples and applications of these notions in analysis and group theory. Moreover, we introduce a new notion of smallness which we call Haar meager sets. This notion coincides with the meager sets in locally compact groups. However, it is strictly stronger in the setting of nonlocally compact groups. We argue that this is the right topological analogue of Christian's Haar null sets. The speaker gratefully acknowledges the support of the LMS under a Scheme 2 Grant.