Tue, 23 Feb 2016

15:45 - 16:45
L4

Log stable maps and Morse theory of toric varieties

William (Danny) Gillam
(Bogazici University Turkey)
Abstract

We will discuss a result to the effect that the moduli space of log stable maps to a toric variety X is "the same" as the Morse-theoretic moduli space of broken gradient flow lines in the "differentiable realization" Y of the fan for X.  This is joint work with Sam Molcho.

Tue, 16 Feb 2016

15:45 - 16:45
L4

The K3 category of a cubic fourfold

Daniel Huybrechts
(Bonn)
Abstract

Smooth cubic fourfolds are linked to K3 surfaces via their Hodge structures, due to work of Hassett, and via Kuznetsov's K3 category A. The relation between these two viewpoints has recently been elucidated by Addington and Thomas. 
We study both of these aspects further and extend them to twisted K3 surfaces, which in particular allows us to determine the group of autoequivalences of A for the general cubic fourfold. Furthermore, we prove finiteness results for cubics with equivalent K3 categories and study periods of cubics in terms of generalized K3 surfaces.

The Impact of Collagen Fibril Polarity on Second Harmonic Generation Microscopy.
Couture, C Bancelin, S Van der Kolk, J Popov, K Rivard, M Légaré, K Martel, G Richard, H Brown, C Laverty, S Ramunno, L Légaré, F Biophysical journal volume 109 issue 12 2501-2510 (Dec 2015)
Fri, 26 Feb 2016

16:00 - 17:00
L1

Self-awareness, assertiveness & productive relationships

Alison Trinder and Dave Hewett
Abstract

Who are you?  What motivates you?  What's important to you?  How do you react to challenges and adversities?  In this session we will explore the power of self-awareness (understanding our own characters, values and motivations) and introduce assertiveness skills in the context of building positive and productive relationships (with colleagues, collaborators, students and others).

Fri, 19 Feb 2016

16:00 - 17:00
L1

North meets South Colloquium

Patrick Farrell + Yufei Zhao
(University of Oxford)
Abstract

Computing distinct solutions of differential equations -- Patrick Farrell

Abstract: TBA

Triangles and equations -- Yufei Zhao

Abstract: I will explain how tools in graph theory can be useful for understanding certain problems in additive combinatorics, in particular the existence of arithmetic progressions in sets of integers. 

Fri, 22 Jan 2016

16:00 - 17:00
L1

Scientific writing

Prof. Nick Trefethen
(Mathematical Institute, Oxford)
Abstract

Writing is a part of any career in science or mathematics. I will make some remarks about the role writing has played in my life and the role it might play in yours.

Thu, 03 Mar 2016

14:00 - 15:00
Rutherford Appleton Laboratory, nr Didcot

Sparse iterative solvers on GPGPUs and applications

Dr Salvatore Filippone
(Cranfield University)
Abstract

We will review the basic building blocks of iterative solvers, i.e. sparse matrix-vector multiplication, in the context of GPU devices such 
as the cards by NVIDIA; we will then discuss some techniques in preconditioning by approximate inverses, and we will conclude with an 
application to an image processing problem from the biomedical field.

Mon, 22 Feb 2016
14:15
L4

The Gromoll filtration, Toda brackets and positive scalar curvature

OAC-manifolds meeting: Diarmuid Crowley
(Aberdeen)
Abstract
An exotic (n+1)-sphere has disc of origin D^k if k is the smallest integer such that some clutching diffeomorphism of the n-disc which builds the exotic sphere can be written as an (n-k)-parameter family of diffeomorphisms of the k-disc.
 
In this talk I will present a new method for constructing exotic spheres with small disc of origin via Toda brackets.  
 
This method gives exotic spheres in all dimensions 8j+1 and 8j+2 with disc of origin 6 and with Dirac operators of non-zero index (such spheres are often called "Hitchin spheres").
 
I will also briefly discuss implications of our results for the space of positive scalar curvature metrics on spin manifolds of dimension 6 and higher, and in particular the relationship of this project to the work of Botvinnik, Ebert and Randal-Williams.
 
This is part of joint work with Thomas Schick and Wolfgang Steimle.
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