Fri, 18 Jun 2010

10:00 - 11:30
DH 3rd floor SR

DPhil student transfer of status presentations

Various
(Oxford)
Abstract

Puck Rombach;

"Weighted Generalization of the Chromatic Number in Networks with Community Structure",

Christopher Lustri;

"Exponential Asymptotics for Time-Varying Flows,

Alex Shabala

"Mathematical Modelling of Oncolytic Virotherapy",

Martin Gould;

"Foreign Exchange Trading and The Limit Order Book"

Tue, 16 Feb 2010

15:45 - 16:45
L3

Moduli Spaces of Sheaves on Toric Varieties

Martijn Kool
(Oxford)
Abstract

Extending work of Klyachko, we give a combinatorial description of pure equivariant sheaves on a nonsingular projective toric variety X and use this description to construct moduli spaces of such sheaves. These moduli spaces are explicit and combinatorial in nature. Subsequently, we consider the moduli space M of all Gieseker stable sheaves on X and describe its fixed point locus in terms of the moduli spaces of pure equivariant sheaves on X. As an application, we compute generating functions of Euler characteristics of M in case X is a toric surface. In the torsion free case, one finds examples of new as well as known generating functions. In the pure dimension 1 case using a conjecture of Sheldon Katz, one obtains examples of genus zero Gopakumar-Vafa invariants of the canonical bundle of X.

Tue, 02 Mar 2010

15:45 - 16:45
L3

Thom polynomials and the Green-Griffiths conjecture

Gergely Berczi
(Oxford)
Abstract

The Green-Griffiths conjecture from 1979 says that every projective algebraic variety $X$ of general type contains a certain proper algebraic subvariety $Y$ such that all nonconstant entire holomorphic curves in $X$ must lie inside $Y$. In this talk we explain that for projective hypersurfaces of degree $d>dim(X)^6$ this is the consequence of a positivity conjecture in global singularity theory.

Thu, 18 Feb 2010
11:00
DH 3rd floor SR

Submarine Hunting and Other Applications of the Mathematics of Tracking. (NOTE Change of speaker and topic)

Trevor Wood
(Oxford)
Abstract

The background for the multitarget tracking problem is presented

along with a new framework for solution using the theory of random

finite sets. A range of applications are presented including

submarine tracking with active SONAR, classifying underwater entities

from audio signals and extracting cell trajectories from biological

data.

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