Fridays at 12.15 at Wolfson 4W 1.7. All talks will be broadcast on Zoom.

Link to Zoom meeting

Everyone is welcome at these talks.

Date Speaker Title
6 Oct 2023 Marco Fasondini (Leicester)
Complex-plane singularity dynamics for blow up in a nonlinear heat equation - analysis and computation

Blow-up solutions to a heat equation with spatial periodicity and a quadratic nonlinearity are studied through asymptotic analyses and a variety of numerical methods. The focus is on the dynamics of the singularities in the complexified space domain. Blow up in finite time is caused by these singularities eventually reaching the real axis. The analysis provides a distinction between small and large nonlinear effects, as well as insight into the various time scales on which blow up is approached. It is shown that an ordinary differential equation with quadratic nonlinearity plays a central role in the asymptotic analysis. This equation is studied in detail, including its numerical computation on multiple Riemann sheets, and the far-field solutions are shown to be given at leading order by a Weierstrass elliptic function. This is joint work with J.R. King (Nottingham) and J.A.C Weideman (Stellenbosch).
13 Oct 2023 Ioannis Papadopoulos (Imperial)
A sparse hp-finite element method for the screened Poisson equation posed on disks, annuli and cylinders

We introduce a sparse and very high order hp-finite element method for the weak form of the screened Poisson equation. The domain may be a disk, an annulus, or a cylinder. The cells of the mesh are an innermost disk (omitted if the domain is an annulus) and concentric annuli. We demonstrate the effectiveness of this method on PDEs with radial direction discontinuities in the coefficients and data. The discretization matrix is symmetric positive-definite. Moreover, the Fourier modes decouple, reducing a two-dimensional PDE solve to a series of one-dimensional solves that may be computed in parallel, scaling with linear complexity. We also utilize the ADI method of Fortunato and Townsend to apply the method to a 3D cylinder with a quasi-optimal complexity solve.
20 Oct 2023 Seb Scott (Bath)
TBC

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27 Oct 2023 Alexander Bastounis (Leicester)
TBC

TBC
3 Nov 2023 Alexander Belozerov (Bath)
TBC

TBC
10 Nov 2023 TBC
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17 Nov 2023 Winfried Auzinger (TU Wien)
TBC

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24 Nov 2023 TBC
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TBC
1 Dec 2023 Coralia Cartis (Oxford)
TBC

TBC
8 Dec 2023 MMath Year Long Project (YLP) talks
TBC

TBC
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How to get to Bath See here for instructions how to get to Bath. Please email Pranav Singh (ps2106@bath.ac.uk) if you intend to come by car and require a parking permit for Bath University Campus for the day.
Tips for giving talks

Tips for new students on giving talks

Since the audience of the NA seminar contains both PhD students and staff with quite wide interests and backgrounds, the following are some guidelines/hints to make sure people don't give you evil looks at lunch afterwards.

Before too much time passes in your talk, ideally the audience should know the answers to the following 4 questions:

  • What is the problem you're considering?
  • Why do you find this interesting?
  • What has been done before on this problem/what's the background?
  • What is your approach/what are you going to talk about?

There are lots of different ways to communicate this information. One way, if you're doing a slide show, could be for the first 4 slides to cover these 4 questions; although in this case you may want to revisit these points later on in the talk (e.g. to give more detail).

Remember:

  • "vertebrate style" (structure hidden inside - like the skeleton of a vertebrate) = good for detective stories, bad for maths talks.
  • "crustacean style" (structure visible from outside - like the skeleton of a crustacean) = bad for detective stories, good for maths talks.