12 November 2014

16:00

12 November 2014

16:00

29 October 2014

16:30

Szymon Dolecki

29 October 2014

15:00

Paul Gartside

29 October 2014

14:00

Robin Knight

Abstract

Counterexamples to Vaught's Conjecture regarding the number of countable

models of a theory in a logical language, may felicitously be studied by investigating a tree

of types of different arities and belonging to different languages. This

tree emerges from a category of topological spaces, and may be studied as such, without

reference to the original logic. The tree has an intuitive character of absoluteness

and of self-similarity. We present theorems expressing these ideas, some old and some new.

29 October 2014

12:00

29 October 2014

11:00

Istvan Juhasz

29 October 2014

10:45

to

17:00

22 October 2014

16:00

Robert Leek

Abstract

Using an internal characterisation of radiality or

> Fréchet-Urysohness, we can translate this property into other structural

> forms for many problems and classes of spaces. In this talk, I will

> recap this internal characterisation and translate the properties of

> being radial / Fréchet-Urysohn (Stone-Čech, Hewitt) into the prime ideal

> structure on C*(X) / C(X) for Tychonoff spaces, with a view to reaching

> out to other parts of algebra, e.g. C*-algebras, algebraic geometry, etc.

> Fréchet-Urysohness, we can translate this property into other structural

> forms for many problems and classes of spaces. In this talk, I will

> recap this internal characterisation and translate the properties of

> being radial / Fréchet-Urysohn (Stone-Čech, Hewitt) into the prime ideal

> structure on C*(X) / C(X) for Tychonoff spaces, with a view to reaching

> out to other parts of algebra, e.g. C*-algebras, algebraic geometry, etc.

15 October 2014

16:00

18 June 2014

16:00

Leobardo Fernandez Ramon

Abstract

<p><span> A continuum is a non-empty compact connected metric space. Given a continuum X let P(X) be the power set of X. We define the following set functions:</span><br /><span>T:P(X) to P(X) given by, for each A in P(X), T(A) = X \ { x in X : there is a continuum W such that x is in Int(W) and W does not intersect A}</span><br /><span>K:P(X) to P(X) given by, for each A in P(X), K(A) = Intersection{ W : W is a subcontinuum of X and A is in the interior of W}</span><br /><span>S:P(X) to P(X) given by, for each A in P(X), S(A) = { x in T(A) : A intersects T(x)}</span><br /><span>Some properties and relations between these functions are going to be presented.</span></p>