Postgraduate Seminars Summer 2015

These seminars (unless otherwise stated) will take place on Thursdays at 5pm in Room 500 the Mathematics Department on an (almost) weekly basis - see how to find us for further details. Talks are being given by 2nd and 3rd year Mathematics PhD students for PhD students. They are generally followed by tea and biscuits in the Mathematics Department Staff Room (Room 606, 25 Gordon Street).

30th April 2015

Sam Brown

Title: The Banach-Tarski Paradox

The Banach-Tarski paradox says that it is possible to cut up a ball, and reassemble the pieces into two copies of the original ball. This is one of the most famous "paradoxes" in maths, because it is easy to state but very counterintuitive. I will give an accessible proof (no post-first-year maths will be required) that you will be able to repeat in the pub to your fascinated friends whenever the subject comes up.

Wednesday 6th May 2015 in Room D103

Niko Laaksonen

Title: Hyperbolic Lattice Point Problems

Starting with a brief history of the topic, we will see how different counting problems have a natural interpretation coming not only from the obvious geometric setup, but from an arithmetic point of view as well. In the hyperbolic space there are many complications introduced by the odd geometry and an excess of eigenvalues, for example. We will see how this relates to the heat and wave flow on our manifold and, in particular, how this impacts the problem in different dimensions.

14th May 2015

Matthew Wright

Title: Time travel in general relativity

I will discuss the possibility of general relativity allowing time travel. I will talk about various solutions that allow closed time like curves, such as wormholes. I will then consider various paradoxes that this leads to,  and possible ways of resolving them.

21st May 2015

Pietro Servini

Title: ... And Icarus Flew

In Greek mythology, Icarus - son of the master craftsman Daedalus - on wings made of feather and wax, flew too close to the sun: the wax melted and Icarus fell into the Icarian Sea, where he drowned.  In this talk, I will introduce some of the main concepts of flight and chart humankind's discovery of them; discoveries that have allowed us to go from developing more aerodynamic spears to inventing vehicles that fly hundreds of times faster than Icarus could ever fly and sending spacecraft distances greater than Icarus ever thought existed.​

28th May 2015

Rafael Prieto Curiel

Title: The mathematics of policing

Research concerning social issues, like crime, is a multidisciplinary task that requires Social Scientists, Urban Planners, Engineers, Statisticians and without a doubt, Mathematicians. There are broad types of models that have been used for criminal issues, and some make use of great parts of the spectrum of Applied Mathematical tools, like spatial models, pattern recognition methods, network analysis, time series, complexity and agent based models, partial differential equations and dynamical systems.

Crime can be analysed from the perspective of the criminal, the victim, the place where it occurred and can focus on the reasons why it happened or the impact that it has. However, research should not stop there and should be focused on how to use the many results obtained through the many models to improve our society, either by doing prevention, prediction, reaction or analysis of the crime. For that reason, a key component has to be the work of the police forces.

Questions like how many police officers are needed and where to allocate them will be tackled during the presentation. Real data from Mexico City will be used and presented to show the extreme relevance and the impact of a good mathematical model in improving our social well-being.

4th June 2015

Matthew Scroggs

Title: Numerically Solving PDEs with Finite and Boundary Element Methods

Many real life situations give rise to Partial Differential Equations (PDEs) which cannot be solved analytically. In these cases, fast numerical methods are needed to allow computers to find the solutions to a high degree of accuracy. Two popular methods within science and engineering are the Finite Element Method (FEM) and the Boundary Element Method (BEM).

11th June 2015

Dimitra Kyriakopoulou

Title: Applications of Homology to Analysis

Homology is an algebraic topological concept with applications in various fields. We will look at some of its early applications to analysis; in particular, fixed point theorems, the Leray-Shauder Degree, and Morse theory. Additionally we will see the homology of Lie groups.

18th June 2015

Ryan Palmer

Title: …Why am I waiting so long? - Queueing for healthcare

Recently within the media the NHS has been criticized for long wait times and poor access to care. With an ageing population and constrained budgets, how can healthcare planners better use their resources to continue a high level of accessible care and meet high levels of demand?

Over the last 60 plus years operational research (OR) methods have been used to tackle these sorts of problems in healthcare. Within a range of settings, from acute care to community care,  evaluations of system performance such as length waiting times or resource utilisation have been modelled using OR to provide valuable and actionable insight.

This presentation will include a brief introduction to queueing theory (a branch of OR), some important results and an application from the USA.

30th July 2015 at 5:30pm

Samire Balta

Title: Fluid-body interactions within a channel including branching networks

Solid-solid and solid-fluid impacts and flow in branching vessels are the concern here. The aim is to develop mathematical models and analysis for certain problems in fluid-solid and solid-solid interaction including flow in branching net-works. The underlying inspiration is from natural, biological, medical and indus-trial applications. First, understanding of a body motion within a surrounding fluid will be considered with existing techniques for fluid-flow study and body-motion study. The second aim is to investigate flow in bifurcations, multi-branching ves-sels, reconnections and larger networks.