Fri, 22 Nov 2019

16:00 - 17:00
L1

North Meets South

Abstract

Speaker: Daniel Woodhouse (North)
Title: Generalizing Leighton's Graph Covering Theorem
Abstract: Before he ran off and became a multimillionaire, exploiting his knowledge of network optimisation, the computer scientist F. Thomas Leighton proved an innocuous looking result about finite graphs. The result states that any pair of finite graphs with isomorphic universal covers have isomorphic finite covers. I will explain what all this means, and why this should be of tremendous interest to group theorists and topologists.

Speaker: Benjamin Fehrman (South)
Title: Large deviations for particle processes and stochastic PDE
Abstract: In this talk, we will introduce the theory of large deviations through a simple example based on flipping a coin.  We will then define the zero range particle process, and show that its diffusive scaling limit solves a nonlinear diffusion equation.  The large deviations of the particle process about its scaling limit formally coincide with the large deviations of a certain ill-posed, singular stochastic PDE.  We will explain in what sense this relationship has been made mathematically precise.

Fri, 08 Nov 2019

16:00 - 17:00
L1

North Meets South

Joseph Keir and Priya Subramanian
Abstract

Speaker: Joseph Keir (North)
Title: Dispersion (or not) in nonlinear wave equations
Abstract: Wave equations are ubiquitous in physics, playing central roles in fields as diverse as fluid dynamics, electromagnetism and general relativity. In many cases of these wave equations are nonlinear, and consequently can exhibit dramatically different behaviour when their solutions become large. Interestingly, they can also exhibit differences when given arbitrarily small initial data: in some cases, the nonlinearities drive solutions to grow larger and even to blow up in a finite time, while in other cases solutions disperse just like the linear case. The precise conditions on the nonlinearity which discriminate between these two cases are unknown, but in this talk I will present a conjecture regarding where this border lies, along with some conditions which are sufficient to guarantee dispersion.

Speaker: Priya Subramanian (South)
Title: What happens when an applied mathematician uses algebraic geometry?
Abstract: A regular situation that an applied mathematician faces is to obtain the equilibria of a set of differential equations that govern a system of interest. A number of techniques can help at this point to simplify the equations, which reduce the problem to that of finding equilibria of coupled polynomial equations. I want to talk about how homotopy methods developed in computational algebraic geometry can solve for all solutions of coupled polynomial equations non-iteratively using an example pattern forming system. Finally, I will end with some thoughts on what other 'nails' we might use this new shiny hammer on.

 

Fri, 29 Nov 2019

16:00 - 17:00
L1

Preparing grants and job applications

Jason Lotay, Anna Seigal and Dominic Vella
Abstract

Dominic Vella will talk about writing grants, Anna Seigal will talk about writing research fellow applications and Jason Lotay will talk about his experience and tips for applying for faculty positions. 

 

Tue, 03 Dec 2019
14:30
L1

Estimation of ODE models with discretization error quantification

Takeru Matsuda
(University of Tokyo)
Abstract

We consider estimation of ordinary differential equation (ODE) models from noisy observations. For this problem, one conventional approach is to fit numerical solutions (e.g., Euler, Runge–Kutta) of ODEs to data. However, such a method does not account for the discretization error in numerical solutions and has limited estimation accuracy. In this study, we develop an estimation method that quantifies the discretization error based on data. The key idea is to model the discretization error as random variables and estimate their variance simultaneously with the ODE parameter. The proposed method has the form of iteratively reweighted least squares, where the discretization error variance is updated with the isotonic regression algorithm and the ODE parameter is updated by solving a weighted least squares problem using the adjoint system. Experimental results demonstrate that the proposed method improves estimation accuracy by accounting for the discretization error in a data-driven manner. This is a joint work with Yuto Miyatake (Osaka University).

Fri, 25 Oct 2019

17:30 - 18:30
L1

Jon Chapman - Waves and resonance: from musical instruments to vacuum cleaners, via metamaterials and invisibility cloaks

Jon Chapman
(University of Oxford)
Further Information

Oxford Mathematics Public Lectures 

Jon Chapman - Waves and resonance: from musical instruments to vacuum cleaners, via metamaterials and invisibility cloaks.

Friday 25 October 2019

5.30pm-6.30pm, Mathematical Institute, Oxford

Please email @email to register.

Watch live:
https://facebook.com/OxfordMathematics
https://livestream.com/oxuni/chapman

Jon Chapman is Professor of Mathematics and its Applications in Oxford.

The Oxford Mathematics Public Lectures are generously supported by XTX Markets.

Tue, 03 Dec 2019
14:00
L1

On symmetrizing the ultraspherical spectral method for self-adjoint problems

Mikael Slevinsky
(University of Manitoba)
Abstract

A mechanism is described to symmetrize the ultraspherical spectral method for self-adjoint problems. The resulting discretizations are symmetric and banded. An algorithm is presented for an adaptive spectral decomposition of self-adjoint operators. Several applications are explored to demonstrate the properties of the symmetrizer and the adaptive spectral decomposition.

 

Mon, 02 Dec 2019

17:30 - 18:30
L1

Carlo Rovelli - Spin networks: the quantum structure of spacetime from Penrose's intuition to Loop Quantum Gravity

Carlo Rovelli
(Université d'Aix-Marseille)
Further Information

Oxford Mathematics Public Lectures- The Roger Penrose Lecture

Carlo Rovelli  - Spin networks: the quantum structure of spacetime from Penrose's intuition to Loop Quantum Gravity

Monday 2 December 2019

In developing the mathematical description of quantum spacetime, Loop Quantum Gravity stumbled upon a curious mathematical structure: graphs labelled by spins. This turned out to be precisely the structure of quantum space suggested by Roger Penrose two decades earlier, just on the basis of his intuition. Today these graphs with spin, called "spin networks" have become a common tool to explore the quantum properties of gravity. In this talk Carlo will tell this beautiful story and illustrate the current role of spin networks in the efforts to understand quantum gravity.

Carlo Rovelli is a Professor in the Centre de Physique Théorique de Luminy of Aix-Marseille Université where he works mainly in the field of quantum gravity and  is a founder of loop quantum gravity theory. His popular-science book 'Seven Brief Lessons on Physics' has been translated into 41 languages and has sold over a million copies worldwide.

5.30pm-6.30pm, Mathematical Institute, Oxford

Please email @email to register.

Watch live:
https://facebook.com/OxfordMathematics
https://livestream.com/oxuni/rovelli

The Oxford Mathematics Public Lectures are generously supported by XTX Markets.

Sun, 12 May 2019

13:00 - 14:00
L1

Matt Parker at the Oxford Maths Festival

Matt Parker
(Queen Mary University London)
Further Information

Matt Parker is a stand-up comedian and mathematician. He appears regularly on TV and online and is a presenter on the Discovery Channel. As part of the comedy group Festival of the Spoken Nerd, Matt has toured worldwide and is the first person to use an overhead projector on-stage at the Hammersmith Apollo since Pink Floyd.

Previously a maths teacher, Matt visits schools to talk to students about maths as part of Think Maths and he is involved in the Maths Inspiration shows. He is the Public Engagement in Mathematics Fellow at Queen Mary University of London.

Matt is coming to the Oxford Maths Festival on 12 May and will be signing copies of his new book 'Humble Pi' after his talk. To book a space at this talk, please visit https://mathsfest.web.ox.ac.uk/event/matt-parker. Suitable for ages 16+.

Fri, 31 May 2019

16:00 - 17:00
L1

Careers beyond academia

Katia Babbar (AI Wealth Technologies & QuantBright), Jara Imbers (Risk Management Solutions) and Tom Hawes (Smith Institute)
Abstract

A panel discussion on non-academic careers for mathematicians with PhDs, featuring Katia Babbar (AI Wealth Technologies & QuantBright), Jara Imbers (Risk Management Solutions) and Tom Hawes (Smith Institute).
 

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