Mon, 15 Jun 2015

16:00 - 17:00
C2

Almost similar p-adic representations: crystalline versus étale.

Junghwan Lim
(Oxford)
Abstract

I will introduce the general idea of p-adic Hodge theory from the view point of a beginner. Also, I will give a sketch of the proof of the crystalline comparison theorem in the case of good reduction using 'almost mathematics'.

 

Mon, 01 Jun 2015

16:00 - 17:00
C2

Perfectoid spaces and the tilting equivalence

Alex Betts
(Oxford)
Abstract

We will give a sketch overview of Scholze's theory of perfectoid spaces and the tilting equivalence, starting from Huber's geometric approach to valuation theory. Applications to weight-monodromy and p-adic Hodge theory we will only hint at, preferring instead to focus on examples which illustrate the philosophy of tilting equivalence.
 

Mon, 27 Apr 2015

16:00 - 17:00
C2

Langlands Functoriality for Symplectic Groups

Benjamin Green
(Oxford)
Abstract

In this talk I will describe two instances of Langlands functoriality concerning the group $\mathrm{Sp}_{2n}$. I will then very briefly explain how this enables one to attach Galois representations to automorphic representations of (inner forms of) $\mathrm{Sp}_{2n}$. 

Thu, 18 Jun 2015

17:00 - 18:00
L2

TheLMS Hardy Lecture: The famous inverse scattering transform method and its less famous discrete version

Prof Nalini Joshi
(University of Sydney)
Abstract

Abstract: The simplest solutions of integrable systems are special functions that have been known since the time of Newton, Gauss and Euler. These functions satisfy not only differential equations as functions of their independent variable but also difference equations as functions of their parameter(s).  We show how the inverse scattering transform method, which was invented to solve the Korteweg-de Vries equation, can be extended to its discrete version.

S.Butler and N.Joshi, An inverse scattering transform for the lattice potential KdV equation, Inverse Problems 26 (2010) 115012 (28pp)

Tue, 09 Jun 2015

17:00 - 18:00
C2

TBA

Benjamin Klopsch
(Duesseldorf)
Thu, 21 May 2015

16:00 - 17:00
L5

Anabelian Geometry with étale homotopy types

Jakob Stix
(University of Heidelberg)
Abstract

Classical anabelian geometry shows that for hyperbolic curves the etale fundamental group encodes the curve provided the base field is sufficiently arithmetic. In higher dimensions it is natural to replace the etale fundamental group by the etale homotopy type. We will report on progress obtained in this direction in a recent joint work with Alexander Schmidt.

 

**Joint seminar with Logic. 

Thu, 18 Jun 2015

17:30 - 18:30
L6

On the Consistency Problem for Quine's New Foundations, NF

Peter Aczel
(Manchester)
Abstract

In 1937 Quine introduced an interesting, rather unusual, set theory called New Foundations - NF for short.  Since then the consistency of NF has been a problem that remains open today.  But there has been considerable progress in our understanding of the problem. In particular NF was shown, by Specker in 1962, to be equiconsistent with a certain theory, TST^+ of simple types. Moreover Randall Holmes, who has been a long-term investigator of the problem, claims to have  solved the problem by showing that TST^+ is indeed consistent.  But the working manuscripts available on his web page that describe his possible proofs are not easy to understand - at least not by me.

 
In my talk I will introduce TST^+ and its possible models and discuss some of the interesting ideas, that I have understood, that Holmes uses in one of his possible proofs.  If there is time in my talk I will also mention a more recent approach of Jamie Gabbay who is taking a nominal sets approach to the problem.
Thu, 11 Jun 2015

17:30 - 18:30
L6

Examples of quasiminimal classes

Jonathan Kirby
(UEA)
Abstract

I will explain the framework of quasiminimal structures and quasiminimal classes, and give some basic examples and open questions. Then I will explain some joint work with Martin Bays in which we have constructed variants of the pseudo-exponential fields (originally due to Boris Zilber) which are quasimininal and discuss progress towards the problem of showing that complex exponentiation is quasiminimal. I will also discuss some joint work with Adam Harris in which we try to build a pseudo-j-function.

Thu, 04 Jun 2015

17:30 - 18:30
L5

Some effective instances of relative Manin-Mumford

Gareth Jones
(Manchester)
Abstract

In a series of recent papers David Masser and Umberto Zannier proved the relative Manin-Mumford conjecture for abelian surfaces, at least when everything is defined over the algebraic numbers. In a further paper with Daniel Bertrand and Anand Pillay they have explained what happens in the semiabelian situation, under the same restriction as above.

At present it is not clear that these results are effective. I'll discuss joint work with Philipp Habegger and Masser and with Harry Schimdt in which we show that certain very special cases can be made effective. For instance, we can effectively compute a bound on the order of a root of unity t such that the point with abscissa 2 is torsion on the Legendre curve with parameter t.

 

**Note change of room**

 

 

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