# Events

## MAGIC launch lecture 2021-2022

Sep
30
Thu 2021

16:00 - 17:00

Organised by Sam Blackburn.

Hosted by University of East Anglia.

Dear All,

You are invited to join this year’s MAGIC launch lecture on Thursday 30 September at 16:00.

Please do attend if you are able to. Staff, students and researchers are all welcome.

To join please go to “This week” and select the “Join lecture” button which will appear shortly before the start of the lecture.

Please note you will you need to have set up a MAGIC Zoom account to join this live lecture – instructions on how to do this can be found in the "How to join a  live lecture" thread on the MAGIC General Forum.

Should you be unable to join on the day the lecture will be recorded and available to view at a later time.

MAGIC Launch Lecture Title: Thermalisation in weakly nonlinear chains
Speaker: Davide Proment (University of East Anglia)
Date: Thursday 30 September 2021 at 16:00 – 17:00

Abstract: I will present some theoretical results on the seminal $\alpha$-Fermi-Pasta-Ulam-Tsingou (FPUT) problem, that is a one-dimensional system formed N=16,32 and 64 masses connected by nonlinear quadratic springs.

The theoretical approach is based on resonant wave-wave interaction theory and wave turbulence theory.

Assuming the weakly nonlinear regime, the one originally considered by Fermi to model heat transport in crystals, I will show that the long time dynamics of the system is ruled by exact discrete wave resonances.

After giving a general introduction to the 1955 Fermi-Pasta-Ulam-Tsingou model, a system that inspired areas in mathematics and physics like integrable systems, ergodic theory, nonlinear waves, and statistical mechanics, I will discuss the main idea of the wave-wave interaction theory and wave turbulence theory.

I will show that the first non-trivial wave resonances correspond to six-wave interactions as solutions of Diophantine equations.

These interactions are responsible for the thermalisation process in the FPUT system and explain its extremely long time scale.

Numerical simulations supporting out theoretical predictions will be briefly discussed (based on the joint work with Miguel Onorato, Lara Vozella and Yuri V. L'vov entitled "A route to thermalisation in the $\alpha$-Fermi-Pasta-Ulam(-Tsingou) system", PNAS 112, 4208-4213, 2005)

Kind regards,

Sam Blackburn

## MAGIC launch lecture 2020-2021

Oct
1
Thu 2020

16:00 - 17:00

Organised by Sam Blackburn.

Hosted by Durham University.

Oct
15
Tue 2019

14:10 - 14:30

Hosted by University of Exeter.

Oct
3
Thu 2019

15:00 - 16:00

Organised by Sam Blackburn.

Hosted by Durham University.

Oct
3
Thu 2019

10:00 - 11:30

Organised by Professor Peter Ashwin.

Hosted by University of Exeter.

Mar
6
Wed 2019

14:05 - 14:14

Feb
28
Thu 2019

14:00 - 15:00

Organised by Sam Blackburn.

Hosted by University of Newcastle.

Feb
26
Tue 2019

16:00 - 17:30

Organised by Sam Blackburn.

Hosted by University of Exeter.

Jan
18
Fri 2019

10:05 - 10:20

Organised by Dr Martina Balagovic.

Hosted by University of Newcastle.

Jan
14
Mon 2019

10:00 - 10:30

Organised by Dr Martina Balagovic.

Hosted by University of Newcastle.

Jan
11
Fri 2019

11:45 - 12:30

Organised by Dr Martina Balagovic.

Hosted by University of Newcastle.

Jan
11
Fri 2019

11:45 - 12:30

Organised by Dr Martina Balagovic.

Hosted by University of Newcastle.

Dec
18
Tue 2018

10:30 - 12:30

Organised by Dr Omar Lakkis.

Hosted by University of Sussex.

Dec
17
Mon 2018

10:05 - 10:55

Organised by Dr Omar Lakkis.

Hosted by University of Sussex.

Oct
4
Thu 2018

16:05 - 16:55

Organised by Professor Peter Ashwin.

Hosted by University of Manchester.