UK Nonlinear News Issue 66, Mar 2012

Articles and Reviews

  • The PANDA (Patterns, Nonlinear Dynamics and Applications) meeting held at Leeds on 20th January marked the 10th anniversary of this successful LMS-funded series of workshops. There have been three or four meetings each year since December 2001. This workshop had about 30 participants, a third of whom were postgraduate students.
    Jonathan Dawes, one of the originators of PANDA (and who coined the acronym) gave a talk that began by summarising the statistics of the series so far. Twenty-seven meetings have been held, featuring 162 talks given by 137 speakers, including 10 from overseas. He noted some recent successes within the field of nonlinear dynamics and discussed two particular areas of rapidly increasing interest: network problems, where subsystem dynamics and connectivity combine to produce system-level responses, and climate modelling, where for example the concept of a 'tipping point' can be given substantial mathematical content. Future challenges in the nonlinear systems field include 'known unknowns', such as the behaviour of traffic and crowds, dry friction, and viscoelastic and liquid crystal continuum mechanics, as well as the 'unknown unknowns' which have so far received little attention from those in the field, for example spatial homogenisation, discrete event dynamics and viewing dynamical systems as information processing systems. He challenged the community to move beyond its 'comfort zone' of ordinary and partial differential equations and to address physical and biological applications more realistically, in order to improve the relatively low profile of the field, as indicated by the recent International Review of Mathematics.
    The other talks covered a wide range of topics. Suzanne Fielding (Durham) addressed the dynamics of a fluid with rod-like swimming bacteria with extensile or contractile properties. Near a phase transition from isotropic to nematic behaviour, superfluid behaviour can occur, leading to spontaneous 'shear banding' flow. In two dimensions this shear flow can become unstable, leading to either regular circulating patterns or unsteady irregular patterns.
    Gustav Delius (York) spoke on wave instabilities in size spectrum models. His starting point was the observation that the abundance of marine organisms exhibits a power law scaling with the organism size. Noting that traditional species-based predator-prey models may not be valid since predators are themselves prey when small, he proposed a model based entirely on organism size. In the continuum limit this yields a non-local model with integral terms representing the predation of larger organisms on smaller ones. This model is scale-invariant, leading to a steady-state power law solution. However, this state can be unstable, leading to travelling waves patterns in the organism abundance as a function of size.
    Rachel Taylor (Heriot-Watt) spoke on seasonal forcing and multi-year cycles in predator-prey models. Her system was based on a standard ODE model, but included the feature that the prey growth rate fluctuates sinusoidally, representing seasonal effects. This leads to a wealth of complicated dynamics as the amplitude of this fluctuation is varied, including period-doubling bifurcations and Arnol'd tongues arising from resonance between the seasonal forcing and the natural oscillation period of the predator-prey system.
    The final talk, given by Thomas Wagenknecht (Leeds), returned to more familiar PANDA territory - the currently trendy topic of 'homoclinic snaking' in the subcritical Swift-Hohenberg system. Strongly localised solutions can be found in the subcritical regime, representing a heteroclinic connection between the zero state and the periodic pattern (viewed as a periodic orbit in phase space). Different mechanisms can disrupt this snaking behaviour. One is the breaking of the left-right symmetry of the system, and another is a local bifurcation of the patterned state. In the presence of one of these mechanism, the snaking structure can break up into isolas. This had previous been demonstrated numerically, but Thomas explained how this could be shown rigorously using the methods of spatial dynamics and geometric analysis.
    The lectures were interesting and there was plenty of discussion after each talk and during the breaks. We are very grateful for the ongoing support of the LMS, which has allowed this series of workshops to provide a friendly atmosphere for postgraduate students to present their work, and to build a strong sense of community in this subject area over the last ten years.
    Paul Matthews
    Alastair Rucklidge

News

  • The Institute for Complex Systems and Mathematical Biology (King's College, University of Aberdeen) has hired three new Academic Staff:
    Prof Antonio Politi, Chair Professor, from the Centre for Complexity, Florence, Italy
    Dr Francesco Ginelli, Lecturer, from a CNRS Institute, Rome, Italy
    Dr Francisco Perez-Reche, Lecturer, from the Dundee-Albertay University, Dundee, UK
  • The next talk in the MAGIC Access Grid Dynamics seminar series will be on 29 May 2012 at 4pm: Claire Postlethwaite (Auckland) on "Feedback control of patterns arising in equivariant Hopf bifurcation problems".

Jobs

  • The University of Bath is currently offering six Prize Fellowships across the Faculty of Science, aimed at early career researchers. Fellows will be expected to pursue an independent programme of research. Initial appointments will be to a fixed-term Research Fellow post with the expectation of transfer to a permanent Lectureship at the end of year two. It is suggested that potential applicants make contact (via email) with the relevant person before submitting an application. Deadline: 21 May.
  • Zeeman Lectureship in Mathematics and Complexity Science (3 years starting Sept 2012) Warwick.
  • The Institute for Complex Systems and Mathematical Biology, University of Aberdeen are looking to appoint two full-time Lecturers or Senior Lecturers in Applied Mathematics / Physics, who work on the development of methods, techniques and algorithms to handle nonlinear and complex time series and/or to analyse large data sets like the ones found in biology, engineering, economy and the environmental sciences. The jobs are expected to be advertised in the School of Natural and Computing Sciences on 28 March.
  • Postdoctoral Fellowship Temporal regulation of endocrine gene expression - timing in living cells and tissues
    enquiries: Professor David Rand, e-mail: d.a.rand@warwick.ac.uk
  • PhD and Postdoctoral opportunities with the FP7 astrodynamics network

DSWeb Professional Opportunities in Dynamical Systems

Postgraduate opportunities: Leeds  Warwick  Surrey

Meetings, Conferences and Events

Conference Listing by date.

Journal News

  • New journal: Advances in Nonlinear Analysis published by Walter de Gruyter
    Editors in Chief: Vicentiu D. Radulescu (Mathematics Institute of the Romanian Academy) and Marco Squassina (University of Verona)

Issue Sixty Seven: June 2012

Issue Sixty Seven is scheduled for June 2012. Submission of news (new courses, meetings, conferences, new appointments, jobs, new research directions etc.), comments or articles about any aspect of nonlinearity in the UK are very welcome and should arrive by 10 June 2012.