BGU Set Theory and Topology Seminar Archive

 

Next seminar

 

Wednesday, April 24, 14:00, room -101, the math building.

Speaker: Victoria Lubitch

Topic: Linearly Lindelof non Lindelof spaces II

Wednesday, April 10, 14:00, room -101, the math building.

Speaker: Victoria Lubitch

Topic: Linearly Lindelof non Lindelof spaces

Abstract: Construction of sequentially linearly Lindelof space from good scale of cardinality \aleph_{\omega +1} . Construction of realcompact linearly lindelof space under assumption 2^{\omega} = \aleph_{\omega + 1} and existing of good scale. (Partial solution of Archangel'skii problem). Conditions when product of two sequentially linearly Lindelof spaces is linearly Lindelof. Tatch Moore example LLnL space as product regular lindelof space and separable metric space (assumption 2^{\aleph_{\omega}} > \aleph_{\omega+1}). Kunen example of locally compact LLnL space.

Wednesday, March 20, 14:00, room -101(?), the math building.

Speaker: Michael Levin

Topic: Free actions of compact 0-dimensional groups

Abstract: We will discuss basic results, methods and conjectures.

Wednesday, February 27, 12:00, room -101, the math building.

Speaker: Istvan Juhasz (Budapest)

Topic: of his choice

Friday, February 15, 10:00, room -101, the math building.

Speaker: Istvan Juhasz (Budapest)

Topic: Calibers, free sequences and density

Abstract: Results from a joint work with Z. Szentmiklossy. Below you can download the DVI, PS and PDF file.


NOTE: The last seminar in this semester


Wednesday, January 9, 14:30, room 201, the math building.

Speaker: Edmund Ben-Ami

Topic: Another proof of the Open Mapping Principle (III)

Wednesday, January 2, 14:30, room 201, the math building.

Speaker: Arkady Leiderman

Topic: On transitive actions and homogeneous spaces

Wednesday, December 26, 14:00, room 201, the math building.

Speaker: Edmund Ben-Ami

Topic: Another proof of the Open Mapping Principle (II)

Wednesday, December 19, 14:00, room 201, the math building.

Speaker: Edmund Ben-Ami

Topic: Another proof of the Open Mapping Principle

Wednesday, December 12, 14:00, room 201, the math building.

Speaker: Wieslaw Kubis

Topic: Minimal discrete and continuous flows

Abstract: A flow is, by the definition, an action of G on a topological space X, where G is either the group of integers or the group of the real numbers; we add the adjective discrete or continuous to specify the group. An interesting problem is which topological spaces admit minimal flows (a flow is minimal if all its orbits are dense). I will describe some examples and results. Finally, I will prove that if a Hausdorff space X admits a flow whose all forward orbits are dense then X is either compact or else X is nowhere locally compact.

Wednesday, December 5, 14:30, room 201, the math building.

Speaker: Dr. Michael Megrelishvili (Bar-Ilan University)

Topic: Reflexive representations of topological groups and G-spaces

Abstract: The talk will be devoted to the following author's results:

Theorem 1 A topological group G embeds into the isometry group of a reflexive Banach space if and only if weakly almost periodic functions separate points and closed subsets in G.

Theorem 2 The group Homeo_{+} [0,1] of orientation-preserving homeomorphisms of the usual segment [0,1] with the compact-open topology admits no non-trivial strongly continuous representations in reflexive Banach spaces.

Friday, November 30, 10:00, room -101, the math building.

Speaker: Arkady Leiderman

Topic: Actions of general topological groups IV (continuation)

Abstract: The last lecture on effective actions of topological groups.

Wednesday, November 14, 14:00, room 201, the math building.

Speaker: Arkady Leiderman

Topic: Actions of General topological groups III (continuation)

Abstract: Proofs of the two classical theorems due to Teleman and Veech respectively: Every Hausdorff topological group acts effectively on a compact space; every locally compact group acts freely on a compact space.

Wednesday, November 7, 14:00, room 201, the math building.

Speaker: Arkady Leiderman

Topic: Actions of General topological groups II (the continuation)

Abstract: I 'm going to present proofs of the two classical theorems:

Theorem 1 (Teleman) Every Hausdorff topological group acts effectively on a compact space.

Theorem 2 (Veech) Every locally compact group acts freely on a compact space.

Wednesday, October 31, 14:00, room 201, the math building.

Speaker: Arkady Leiderman

Topic: Actions of General topological groups

Abstract: I am planning to give 2 or 3 lectures. In the first lecture I want to remind basic notions from the theory of topological groups. Then, in the next lectures I'd like to present proofs of the two classical theorems:

Theorem 1 (Teleman) Every Hausdorff topological group acts effectively on a compact space.

Theorem 2 (Veech) Every locally compact group acts freely on a compact space.