Forthcoming events in this series


Fri, 04 May 2007
15:15
L3

Partially commutative groups: divisibility, orthogonal systems and universal theory.

Andrew Duncan
(Newcastle)
Abstract
  I shall describe some joint work with Vladimir Remeslennikov and Ilia Kazachkov. Partially commutative groups are groups given by a presentation determined by a graph: vertices are generators and edges define commutation relations. Divisbility and orthogonal systems are tools developed to study these groups. Using them we have descriptions of centralisers of subsets, a good understanding of the centraliser lattice in terms of the underlying graph and have made good progress towards classifying the universal theory of these groups as well as their automorphism groups.
Fri, 20 Apr 2007
15:15
L3

Garside's Solution to the Conjugacy Problem in the Braid Group

Tristram de Piro
(Camerino)
Abstract
  I will discuss Garside's representation of elements of the braid group in terms of "half- twists" and the corresponding solution to the Conjugacy Problem, originally posed by Artin. If time permits, I will discuss some geometric implications of this result.  
Wed, 28 Mar 2007
15:00
L3

Blurred exponentiation and the geometry of exponential fields

Jonathan Kirby
(UIC, Chicago)
Abstract
  I will discuss the proof that the exponential algebraic closure operator on the complex exponential field is isomorphic to the pregeometry which controls the "pseudoexponential" field.  
Fri, 17 Nov 2006
15:15
L3

TBA

Moshe Kamensky
(UEA)
Fri, 10 Jun 2005
12:00
L1

On Groups definable in o-minimal linear structures

Sergei Starchenko
(Notre Dame)
Abstract

Let M be an ordered vector space over an ordered division ring, and G a definably compact, definably connected group definable in M. We show that G is definably isomorphic to a definable quotient U/L, where U is a convex subgroup of M^n and L is a Z-lattice of rank n. This is a joint work with Panelis Eleftheriou.

Fri, 22 Oct 2004
15:15
SR1

Asymptotics and oscillation

John Shackell
(Kent)
Abstract

Much is now known about exp-log series, and their connections with o-

minimality and Hardy fields. However applied mathematicians who work with

differential equations, almost invariably want series involving

trigonometric functions which those theories exclude. The seminar looks at

one idea for incorporating oscillating functions into the framework of

Hardy fields.

Fri, 15 Oct 2004
15:15
SR1

Bounding back and forth through the complex field

Alex Wilkie
(Oxford)
Abstract

The first seminar will be given with the new students in

mind. It will begin with a brief overview of quantifier elimination and its

relation to the back-and-forth property.I shall then discuss complexity issues

with particular reference to algebraically closed fields.In particular,how much

does the height and degree of polynomials in a formula increase when a

quantifier is eliminated? The precise answer here gave rise to the definition

of a `generic' transcendental entire function,which will also be

discussed.