# Weekly bulletin

## Week starting Monday 18 March 2019

### 2pm 19 March - Partial Differential Equations and Analysis Seminar

Start time: 2pm 19 March
Location: Seminar room 1.33, Hanna Neumann Building #145
Presenter(s): Colin Guillarmou, University of Paris-Sud (Orsay)
Abstract:

We show some new rigidity result for the marked length spectrum of closed negatively curved manifolds (and more generally those with Anosov geodesic flows) in any dimension, answering partially a conjecture of Burns-Katok in ’85. The marked length spectrum is the length of closed geodesics, ordered by their free homotopy classes. This is joint work with T. Lefeuvre.

### 12pm 21 March

Start time: 12pm 21 March
Location: Seminar Room 1.33, Hanna Neumann Building #145
Abstract:

A brief introduction to stacks,  bundle gerbes and their applications to T-dualities.

Many examples will be presented so the talk should be accessible to anyone to some background in differential geometry and algebraic topology.

### 4pm 21 March - MSI Colloquium 2019

Start time: 4pm 21 March
Location: Seminar Room 1.33, Building 145, Science Road, ANU
Presenter(s): Prof Robert Coquereaux, Universite de Marseille, Luminy
Abstract:

After introducing several geometrical models that can be used to calculate multiplicities in Lie group theory, we describe associated polytopes whose volumes can be considered as approximations of those multiplicities.

### 11am 22 March - Partial Differential Equations and Analysis Seminar

Start time: 11am 22 March
Location: Seminar room 1.33, Hanna Neumann Building #145
Presenter(s): Masaharu Taniguchi, Okayama University
Abstract:

For a balanced  bistable reaction-diffusion equation, an axisymmetric traveling front has been well known. We prove that an axially asymmetric traveling front with any positive speed does exist  in a balanced bistable reaction-diffusion equation. Our method is as follows. We use a pyramidal traveling front for an unbalanced reaction-diffusion equation whose cross section has a major axis and a minor axis. Preserving the ratio of  the major axis and a minor axis to be a constant  and taking the balanced limit, we obtain a traveling front in a balanced bistable reaction-diffusion equation. The cross section of this traveling front is a compact set with a major axis and a minor axis when the constant ratio is not $1$.

### 3pm 22 March - Quantum mathematics meeting

Start time: 3pm 22 March
Location: Seminar room 1.33, Hanna Neumann Building 145, Science Road, ANU
Presenter(s): John Hutchinson (ANU)
Abstract:

This is the first in a series of lectures on the foundations of quantum mechanics, addressed to mathematicians. Most of the lectures will be by John Hutchinson; later in the semester we will also have volunteer talks by participants on special topics.

Background Requirements:  Some knowledge of finite dimensional complex inner product spaces. Primarily C^n(i.e.  n-tuples of complex numbers), hermitian and unitary matrices/operators in this setting. Faculty, grad students or third year/honours mathematics students would be fine.

When & Where:  First meeting 3.00 — 4.30 Friday 22 March, subsequent meetings begin April 5. Talks will be in the Hannah Neumann Seminar Room 1.37.