Weekly bulletin

Week starting Monday 11 November 2019

25 November - Special year 2019: Computational Mathematics

Location: Seminar Room 1.33 & 1.37, Building #145, Science Road, The Australian National University

Quantifying modelling uncertainty is essential for credible simulation-aided knowledge discovery, prediction and design. This workshop brings together a diverse set of researchers to identify challenges and novel research directions in the field of uncertainty quantification (UQ). Talks will focus on both algorithm development and applications of UQ in areas ranging from aerospace, material and electrical engineering to the environment. The workshop will focus on various issues surrounding high-dimensional parameter spaces, multi-fidelity modelling, parameter inference, optimal experimental design and design under uncertainty.

This event is part of the MSI Special Year 2019 in Computational Mathematics.

Keynote Speakers

  • Karen Willcox, The University of Texas at Austin
  • Helmut Harbrecht, University of Basel 
  • Aurore Delaigle, University of Melbourne 
  • Frances Kuo, University of New South Wales
  • Tiangang Cui, Monash University
  • John Jakeman, Sandia National Laboratories

Organising committee

  • Stephen Roberts, Australian National University
  • John Jakeman, Sandia National Laboratories
  • Tiangang Cui, Monash University
  • Quoc Le Gia, University of New South Wales
  • Katharine Turner,  Australian National University



Code of conduct

The Mathematical Sciences Institute (MSI) special year is committed to ensuring all workshops, conferences and seminars are accessible to a diverse range of participants. We aim to create a safe, respectful and supportive environment to allow free flow of information, discussions and ideas. All staff and students have the right to be treated with courtesy, fairness and professionalism. Discriminatory or harassing behaviour will not be tolerated.

The essential part of maintaining a safe and respectful work environment is to ensure that individuals report any witnessed or experienced discrimination or harassment to the organiser’s attention, or a member of staff you feel comfortable talking to. If you would like to contact the department anonymously, please email admin.research.msi@anu.edu.au.

We ask all participants to review the ANU Code of Conduct and maintain the principles of the document for the duration of the workshop.

10am 26 November - Graduate Seminar

Start time: 10am 26 November
Location: Seminar Room 1.33, Hanna Neumann Building #145
Presenter(s): Gleb Shabernev, ANU

The goal of this talk is to give a brief introduction to the fractal image compression algorithms in a simple and clear way with variety of examples of its action.

11am 28 November - Algebra and Topology Seminar

Start time: 11am 28 November
Location: Seminar room 1.37, Hanna Neumann Building
Presenter(s): Holly Krieger, University of Cambridge

Abstract: To any rational map f of the Riemann sphere, we can associate a collection of invariants given by the eigenvalues of the associated pushforward operator on the space of quadratic differentials with simple poles.  Recently, Buff-Epstein-Koch proved that many of the resulting invariants are dynamical; in particular, they arise from multipliers of periodic cycles of f. We will discuss the possible dynamical significance of the remaining invariants, focusing on a family of quadratic rational maps.

Note: this talk is in Seminar room 1.37, Hanna Neumann Building, rather than the usual room. 

4pm 28 November - MSI Colloquium 2019

Start time: 4pm 28 November
Location: Seminar Room 1.33, Building 145, Science Road, ANU  
Presenter(s): Dr Holly Krieger, University of Cambridge

In the last decade, an exciting program has emerged connecting the arithmetic of elliptic curves to classical questions in complex algebraic dynamics; that is, the study of iteration of maps on complex algebraic varieties.  We will discuss this program and the fruit it has yielded, providing a new and surprising approach to fundamental questions about the interaction between geometry and arithmetic of elliptic curves. 

About the speaker

Born and raised near Chicago, Dr Holly Krieger completed the undergraduate mathematics honors program at University of Illinois at Urbana-Champaign. She went on to gain a master's degree and a Ph.D. from the University of Illinois at Chicago, with initial research interests during graduate school primarily in arithmetic and Diophantine geometry. Under the guidance of Laura DeMarco and Ramin Takloo-Bighash, her thesis work focused on the emerging field of arithmetic dynamics, which studies the relationship between dynamics of one complex variable and the arithmetic geometry of abelian varieties.
Holly followed her PhD work with an NSF postdoctoral fellowship at MIT under the supervision of Bjorn Poonen, during which time she became particularly interested in problems of unlikely intersections in complex dynamics. Since 2016, she has been the Corfield Lecturer at the University of Cambridge as well as a Fellow at Murray Edwards College. She is also well known for her popular mathematics Numberphile YouTube videos.

Dr. Krieger's talk is supported by The Mahler Lectureship, organised by AustMS and AMSI. The Mahler Lectureship is awarded every two years to a distinguished mathematician who preferably works in an area of mathematics associated with the work of Professor Mahler. 

2pm 29 November - MSI Colloquium 2019

Start time: 2pm 29 November
Location: Seminar Room 1.33, Building 145, Science Road, ANU  
Presenter(s): Associate Professor Serena Dipierro, University of Western Australia

Classical minimal surfaces arise from the minimisation of a perimeter functional: for instance, given a domain in the Euclidean space, one minimises the boundary measure in the domain of sets with prescribed conditions along the boundary of the domain. Besides its clear geometric interest, this topic is related to many important problems in partial differential equations and applied maths, such as phase coexistence models and capillarity. While the classical model is purely "local" (the perimeter of a set in a domain only depends on the set in the domain itself), recently, a lot of interest has arisen for "nonlocal" models, in which far-away contributions may significantly influence the shape of the objects taken into account.

In this spirit, we discuss some recent results on a geometric problem of nonlocal type, consisting of the minimisation of a fractional version of the perimeter. In particular, we will discuss the rather unexpected behaviour of the nonlocal minimisers at the boundary of the reference domain.

About the speaker

Serena Dipierro received her PhD in Mathematical Analysis at the International School for Advanced Studies (SISSA, Trieste) in 2012. After PostDoc positions at the Universidad de Chile and University of Edinburgh, and a Humboldt Fellowship, she held permanent positions at the University of Melbourne and the Università di Milano. Since August 2018, she is an Associate Professor at the University of Western Australia.  

Serena's research focuses on partial differential equations, free boundary problems, nonlocal equations, calculus of variations, nonlinear analysis, and applications.