# Weekly bulletin

## Week starting Monday 20 March 2017

### Monday 20 March - Computational Mathematics Seminar

Start time: 4pm
Location:

John Dedman Building 27, Room G35

Presenter(s): Tobias Neckel (Technical University of Munich)
Abstract:

In the field of scientific computing, random effects become increasingly important to allow for an accurate modelling of realistic effects. Random Differential Equations (RODEs) have proven to be one useful mathematical approach for applications with such effects. In this talk, we will introduce the foundations of RODEs, their relation to stochastic differential equations, and methods to solve them numerically. The Kanai-Tajimi earthquake model is used as an example application. An approach to tackle RODEs with typical techniques of Uncertainty Quantification (UQ) and Sparse Grids is discussed.

In addition, we briefly present a parallel approach to solve RODEs efficiently on modern high-performance computing (HPC) architectures, i.e. in our case clusters accelerated by general purpose graphics processing units (GPGPUs) which represent a way to boost computational performance.

### Tuesday 21 March - Partial Differential Equations and Analysis Seminar

Start time: 1.30pm
Location:

John Dedman Building 27, Room G35

Presenter(s): Melissa Tacy (ANU)
Abstract:

Measuring the $L^p$ mass of an eigenfunction allows us to determine its concentration properties. On a manifold without boundary such estimates follow from short time properties of the wave or semiclassical Schr\"odinger propagators. However the presence of a boundary opens the possibility for multiple reflections even in short time. This will lead to greater concentration of the eigenfunction (displayed by higher $L^p$ norms). It is known, for example, that the whispering gallery modes show this higher concentration. In this talk I will discuss the whispering gallery modes from a semiclassical perspective and introduce a method for studying such eigenfunctions semiclassically on general manifolds.

### Tuesday 21 March - Algebra and Topology Seminar

Start time: 3.30pm
Location:

John Dedman Building 27, Room G35.

Presenter(s): David Penneys (Ohio State)
Abstract:

The notion of an algebra makes sense in any monoidal category C4. When the monoidal category has extra structure, we can endow our algebra with the corresponding structure. We will be interested in defining the notion of a C*4 or W*4 (von Neumann) algebra internal to a category C. We will begin by defining a (concrete) rigid C*- tensor category,and highlight the important features for the abstract setting. We will then define a C*/W*- algebra in C in terms of modules for that algebra. One can prove many analogs of basic representation theoretic results for ordinary operator algebras, like the Gelfand-Naimark Theorem or the Stinespring Dilation Theorem. This talk is based on joint work with Corey Jones (arXiv:1611.04620).

### Wednesday 22 March - Graduate Seminar

Start time: 2.30pm
Location:

John Dedman Building G35 (seminar room)

Presenter(s): Shuaige Qiao
Abstract:

The PhD seminar is a weekly seminar held on Wednesday afternoons, at 2:30-3:30pm, for PhD students to talk about their thesis work or other projects.

There is tea in the common room afterwards.

### Thursday 23 March

Start time: 6pm
Location:

Coombs Theatre and Coombs Extension Lobby, Building 8A

Abstract:

Welcome to the new academic year. On behalf of the Mathematical Sciences Institute, I would like to invite you and a guest to attend an exciting special event for our friends, colleagues and community. The MSI will be sponsoring an ANU Film Group screening of the highly acclaimed, Oscar-nominated film “Hidden Figures", which highlights the work of African-American mathematicians Katherine G. Johnson, Dorothy Vaughn, and Mary Jackson in the pioneering NASA spaceflight programs.

Prior to the screening, we’ll be featuring several short talks by our MSI faculty on some particularly interesting aspects of the film's mathematics and the role of diversity in mathematics, followed by an exclusive reception in the Coombs Extension Lobby prior to the start of the film.

Our MSI Friends and Alumni events are part of our efforts to promote the work of our school and make it accessible to the community, so spouses and guests are especially welcome at this event.

#### Date

Thursday 23 March 2017

#### Time:

Talks: 6–6.45pm
Reception and Drinks: 6.45–7.30pm
Film: 7:30pm

#### Location:

Coombs Theatre and Coombs Extension Lobby

#### RSVP:

Please RSVP online by Friday 17 March 2017

We do hope you can make it and very much look forward to seeing you there. Please note that due to the screening of the film, our talk and reception will take place at the Coombs Theatre and Coombs Extension Lobby.

### Friday 24 March

Start time: 11am
Location:

John Dedman Building 27, Room G35

Presenter(s): Xu-Jia Wang (MSI/ANU)
Abstract:

In this reading seminar we will give lectures on the Monge-Ampere equation, a reference book is Figalli’s “Monge-Ampere equation and its applications”. All are welcome.

### Friday 24 March - MSI Honours conference

Start time: 1pm
Location:

John Dedman Building 27, Room G35

Presenter(s): Jerome Barkhan and Qiuyi Li (MSI/ANU)
Abstract:

coming soon.......

### Friday 24 March - Quantum mathematics meeting

Start time: 2.30pm
Location:

John Dedman Building 27, Room JD1177 (meeting room)

Presenter(s): Alexandra Grant (ANU/MSI)
Abstract:

(Note that we are starting early this week, for a double-header talk.)

Alex will tell us how to think of games as providing a semantics for functional programming.

### Friday 24 March - Quantum mathematics meeting

Start time: 3.30pm
Location:

John Dedman Building 27, Room JD1177 (meeting room)

Presenter(s): David Penneys (Ohio State)
Abstract:

David will give us a tutorial on operator algebras in categories more interesting than the category of vector spaces.

Updated:  23 March 2017/Responsible Officer:  Director/Page Contact:  School Manager