Meetings Archive

Operator Growth and Many-Body Quantum Chaos

2.04 The Fry Building, School of Mathematics

An`It from Qubit’ affiliated workshop to be held at the School of Mathematics, University of Bristol

The study of chaos in many-body quantum systems has recently undergone a renaissance made possible by combining insights from quantum field theory, quantum gravity and quantum information. This workshop will bring together a range of researchers from these fields in order to discuss several open problems. Key focus areas will include: How to describe the spreading of operators, quantum information and entanglement in chaotic systems? How can one quantify the notion of operator size and what is its relation to gravity in holographic systems? Can these new insights help in obtaining new fundamental bounds on thermalization and transport in quantum systems?

Workshop Organizer

Mike Blake (University of Bristol)

Key participants include

Richard Davison (Herriot-Watt University)

Jon Keating (University of Oxford)

Vedika Khemani (Stanford University)

Noah Linden (University of Bristol)

Hong Liu * (Massachusetts Institute of Technology)

Andrew Lucas (University of Colorado, Boulder)

Sebastian Müller (University of Bristol)

Adam Nahum (University of Oxford)

Martin Sieber (University of Bristol)

Julian Sonner (University of Geneva)

Alexandre Streicher (IAS/Perimeter Institute)

Brian Swingle (University of Maryland)

Ying Zhao * (IAS)

*to be confirmed.

Registration

We have a limited capacity to accommodate a number of extra participants in this workshop (although we are unlikely to be able to provide any financial support). If you would be interested in participating please complete the following form.

Sponsors

This workshop will be supported by the Simons Collaboration `It From Qubit’, The School of Mathematics and the Institute for Mathematical Physics at the University of Bristol, and the Heilbronn Institute for Mathematical Research.

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Probability, Analysis and Dynamics conference 2021

Date: 7-9 April 2021

University of Bristol

Organisers: Marton Balázs, Edward Crane, Asma Hassannezhad, Kevin Hughes, Thomas Jordan, John Mackay, Bálint Tóth

Invited speakers:

David Aldous (Berkeley)
Keith Ball (Warwick)
Michiel van den Berg (Bristol)
Anthony Carbery (Edinburgh)
Anna Erschler (ENS Paris)
Charles Fefferman* (Princeton)
Alessio Figalli (ETH Zürich)
Maarit Järvenpää (Oulu)
Wilfrid Kendall (Warwick)
Thomas Kurtz (Madison-Wi)
Carlangelo Liverani (Roma Tor Vergata)
Gaven Martin (Massey, New Zealand)
Boris Solomyak (Bar-Ilan)
Gwyneth Stallard (Open University)
Karl-Theodor Sturm (Bonn)
Monica Visan (UCLA)
Benjamin Weiss (Jerusalem)

* To be confirmed

For more information, please visit the conference website.

Registration will open closer to the time.

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Grae Worster- Colloquium

Monday 9th March, 4:00-5:00pm, The Fry Building, LG.02

Fluid dynamics of marine ice sheets

Abstract: Marine ice sheets flow on bedrock that is below sea level and terminate in floating ice shelves.  Fluid dynamics controls the location of the grounding line, where the ice sheet detaches from the bed rock and starts to float, which in turn determines the rate at which grounded ice is transported into the ocean and contributes to sea-level rise.  I will describe some simple laboratory experiments and associated mathematical models that capture the dynamics of marine ice sheets, highlighting the role of the floating shelves in buttressing the grounded ice sheet.  I will also describe a novel fluid-mechanical instability of shear-thinning, radially extensional flows that may describe certain longitudinal fractures in ice shelves. 

If you would like to attend this talk, please register by filling in this short registration form.

As always there will be a wine reception afterwards in the Staff Common room.

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Elmer Rees Memorial Meeting

The Fry Building, LG.22

We are holding a one-day conference in Elmer’s memory and to mark his contribution to UK Mathematics.

There will be a series of speakers throughout the day, both mathematical and personal. Please find the programme for the meeting here.

If you would like to attend this event, please register for your place here.

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Fifth Workshop on Generalised Baire Spaces

The workshop will begin on Monday at 9am and end on Tuesday at 4pm. It is open to everyone.

For more information, please see the conference website.

Description Generalized descriptive set theory studies spaces of functions on uncountable regular cardinals and properties of their definable subsets. This is a relatively new and very active field of set theoretic research. The talks will focus on generalized descriptive set theory and its connections with model theory and infinite combinatorics. There will be two tutorials on connections with model theory.

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Eric Moulines mini-series of lectures

Eric Moulines will be visiting the Heilbronn Institute of Mathematical Research as a Data Science Visitor from 27th January- 31st January. During his stay Eric will be delivering a series of lectures on Convex optimization for machine learning.

Tuesday 28th January 11:00- 12:00 G.09, The Fry Building
Thursday 30th January 13:00- 14:00, G.10, The Fry Building
Friday 31st January 10:00- 11:00, G.09, The Fry Building

Title: Convex optimization for machine learning

Abstract: The purpose of this course is to give an introduction to convex optimization and its applications in statistical learning.

In the first part of the course, I will recall the importance of convex optimisation in statistical learning. I will briefly introduce some useful results of convex analysis. I will then analyse gradient descent algorithms for strongly convex and then convex smooth functions. I will take this opportunity to establish some results on complexity lower bounds for such problems. I will show that the gradient descent algorithm is suboptimal and does not reach the optimal possible speed of convergence. I will the present a strategy to accelerate gradient descent algorithms in order to obtain optimal speeds.

In the second part of the course, I will focus on non smooth optimisation problems. I we will introduce the proximal operator of which I will establish some essential properties. I will then study the proximal gradient algorithms and their accelerated versions.

In a third part, I will look at stochastic versions of these algorithms.

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Heilbronn Colloquium – Leader

26th February 2020

University of Bristol

We are delighted to welcome Imre Leader to the University of Bristol to deliver a Heilbronn Colloquium.

Title: Partition Regular Equations

Abstract:  A finite or infinite matrix M is called ‘partition regular’ if whenever
the natural numbers are finitely coloured there exists a monochromatic
vector x with Mx=0. Many of the classical results of Ramsey theory, such
as van der Waerden’s theorem or Schur’s theorem, may be naturally rephrased
as assertions that certain matrices are partition regular.

While the structure of finite partition regular matrices is well understood,
little is known in the infinite case. In this talk we will review some known
results and then proceed to some recent developments.

The talk will not assume any previous knowledge of the area.

The colloquium will take place in Lecture theatre 2.41, Fry Building at 16:00-17:00 followed by a wine reception in the Fry Common room.

If you would like to attend the talk, please register by filling in this short registration form.

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