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All seminars (unless otherwise stated) will take place on Tuesdays at 3.00pm in Drayton B20 Jevons LT which is located in Drayton House (30 Gordon Street). See the link to the map for Drayton House for further details. There will be tea afterwards in Room 606 in the Mathematics Department (25 Gordon Street, across the street from Drayton House) - see how to find us for further details. If you require any more information on the Applied seminars please contact Prof Slava Kurylev e-mail: y.kurylev AT ucl.ac.uk or tel: 020-7679-7896.
7 October 2014
Dr G El - University of Loughborough
Title: Soliton gas and soliton turbulence in integrable systems
Abstract:
A linear operator pencil P(lambda)=A-lambda B, with self-adjoint coefficients A and B, may have a complicated spectral picture if both operators A, B are sign-indefinite. I will discuss (up to) three examples - a matrix pencil with a very simple structure studied jointly with E B Davies, a simple ODE pencil (joint work in progress with M Seri), and a problem involving a Dirac operator (joint work with D M Elton and I Polterovich) which illustrate some interesting and not yet fully understood phenomena and pose a number of open questions.
14 October 2014
Prof Mikhail Levitin - University of Reading
Title: Complex spectra of self-adjoint linear pencils
Abstract:
A linear operator pencil P(lambda)=A-lambda B, with self-adjoint coefficients A and B, may have a complicated spectral picture if both operators A, B are sign-indefinite. I will discuss (up to) three examples - a matrix pencil with a very simple structure studied jointly with E B Davies, a simple ODE pencil (joint work in progress with M Seri), and a problem involving a Dirac operator (joint work with D M Elton and I Polterovich) which illustrate some interesting and not yet fully understood phenomena and pose a number of open questions.
21 October 2014
Prof Carol Alexander - University of Sussex
Title: Discretization-Invariant Swaps
Abstract:
Please click here for the abstract
28 October 2014
Prof Geoff Vallis - University of Exeter
Title: Some GFD Problems in Global Warming
Abstract:
I will discuss a few problems in Geophysical Fluid Dynamics that arise when considering a planetary atmosphere that is warming. These include the increase in height of the tropopause, the expansion of the Hadley Cell, and a shift in the mid-latitude jets.
4 November 2014 - NO SEMINAR
11 November 2014
Dr Emilian Parau - University of East Anglia
Title: Axisymmetric Solitary Waves on a Ferrofluid Jet
Abstract:
Travelling axisymmetric solitary waves on the surface of a cylindrical ferrofluid jet are investigated. An azimuthal magnetic field is generated by an electric current flowing along a stationary metal rod which is mounted along the axis of the moving jet. A numerical method is used to compute fully nonlinear travelling solitary waves and comparisons with weakly nonlinear theories and experiments are presented.
18 November 2014
Dr Eric Keaveny - Imperial College London
Title: Force-coupling method for self-propelled and Bownian particles
Abstract:
The force-coupling method (FCM) is a regularized multipole technique for the large-scale simulation of particle suspensions. I will discuss two recent advances with FCM, one pertaining to the modelling of active, self-propelled particles and the other to the inclusion of Brownian motion. For self-propelled particles, I will show that flows generated by their active surface modes have a natural representation in FCM, and with minor modifications, the standard FCM approach for passive particles can also be applied to active ones. I will also discuss how to include particle Brownian motion by forcing the fluid surrounding the particles with a white-noise fluctuating stress. By requiring the resulting flow satisfy the usual constraints imposed in FCM, the correct particle velocity correlations emerge, even when higher-order terms, such as the stresslets, are included in the multipole expansion. I will show simulation results demonstrating the effectiveness of these adaptations with some simulations reaching O(10^4-10^5) independent particles.
25 November 2014 - COLLOQUIUM TALK
Prof Beatrice Pelloni - University of Reading
- please see the Departmental Colloquia webpage
2 December 2014 - INFORMAL SEMINAR
Prof Alexei Popov - Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation, Moscow
Title: Parametric theory of parametric resonance
Abstract:
How a child, without knowing the works of Floquet and Hill, finds an optimal way of amplifying the swings? He/she is guided by the current phase of the oscillations. On this way, one can obtain a continuum of elementary solutions and explicit formulae for an increment of the amplification. Applications to photonics are considered.