Meetings Archive

Matrix Society Talk Series – Monday 18 February

Join us on Monday 18 February, 6pm, SM2 for the first of this terms Matrix talks, designed to show off bits of maths that you won’t see in lectures – no special knowledge required!


Title: Password hacking, the de Bruijn way – Dan Fretwell

Abstract: How does one brute force a password of length n? You try all the possibilities of course*.

But what if the machine lets you type until the correct password is entered? Then you can do much better…by using de Bruijn sequences**!

Intrigued? Then come along. There might even be magic***…

(* not recommended)

(** also not recommended, but is definitely better…honest)

(*** a poor attempt at, but probably worth coming for just in case I mess it up)


Title: The Circles of Apollonius – Nick Rome

Abstract: Over 2000 years ago, the Greek mathematician Apollonius of Perga described how given three touching circles you can construct two more that touch each of the original circles. This neat construction is still studied today leading to all sorts of interesting questions in geometry, fractals, group theory and number theory.


The talk will take place in SM2 from 6pm – 7pm. The talk is open to all, booking is not required.
Continue Reading

Colloquium – Dr Ashley Montanaro, University of Bristol

Title: Quantum algorithms from foundations to applications

Quantum computers are designed to use quantum mechanics to outperform any standard, “classical” computer based only on the laws of classical physics. Following many years of experimental and theoretical developments, it is anticipated that quantum computers will soon be built that cannot be simulated by today’s most powerful supercomputers. But to take advantage of a quantum computer requires a quantum algorithm: and designing and applying quantum algorithms requires contributions to be made at all levels of the theoretical “stack”, from underpinning mathematics through to detailed running time analysis. In this talk, I will describe one example of this process. First, an abstract quantum algorithm due to Aleksandrs Belovs is used to speed up classical search algorithms based on the technique known as backtracking (“trial and error”). Then this quantum algorithm can be applied to fundamental constraint satisfaction problems such as graph colouring, sometimes achieving substantial speedups over leading classical algorithms. The talk will aim to give a flavour of the mathematics involved in quantum algorithm design, rather than going into full details.

Further information

The talk will be held in Enderby Lecture Theatre, Physics, from 4pm – 5pm and will be followed by a drinks reception in the Maths common room.

The event is open to University of Bristol staff and students.

Continue Reading

Heilbronn Colloquium – Prof. Marta Casanellas, UPC Universitat Politècnica de Catalunya

Title: From phylogenetics to algebraic geometry

Abstract: Many of the evolutionary models used in phylogenetics can be viewed as algebraic varieties. In this expository talk we will explain the main goals of phylogenetics, introduce evolutionary Markov models on trees, and show how algebraic varieties arise in this context. Moreover, we will see how an in-depth geometric study of these varieties leads to improvements on phylogenetic reconstruction methods. We shall illustrate these improvements by showing results on simulated and real data and by comparing them to widely used methods in phylogenetics.

Further information

The colloquium will take place in Mott Lecturer Theatre in the Physics Building at 16.00-17:00 on Wednesday 12th December. It will be followed by a drinks reception in the Maths Common Room.

To help us plan space and catering, please complete the short registration form if you are planning to come.

Continue Reading

Heilbronn Colloquium Wahl – Professor Nathalie Wahl, University of Copenhagen

We are very pleased to welcome Nathalie Wahl to the University of Bristol for a Heilbronn colloquium.
Nathalie Wahl is a leading expert in algebraic topology, homotopy theory and geometric topology, and is distinguished for her work on homological stability. She is a professor at the University of Copenhagen and is spending the autumn semester at the Isaac Newton Institute.

Title: Homological stability: what is that for?

Abstract: Homological stability is a topological property shared by many configuration spaces and groups of matrices, or, more generally, groups of symmetries. In recent years, it has turned into a powerful computational tool. The talk will give an overview of the subject.

Further information
The colloquium will take place in SM1 in the Main Maths Building at 14.30 on Wednesday 21st November. It will be followed by afternoon tea in the Common Room.
To help us plan space and catering, please complete the short registration form if you are planning to come.
Continue Reading

A3G 2018: Advances in Applied Algebraic Geometry


University of Bristol Organising Committee: Fatemeh Mohammadi 

In recent years, modern algebraic geometry methods have been picked up by applied mathematicians, engineers and computer scientists to solve real-world problems. This conference brings world leaders in this field to Bristol to present their research.

Confirmed Speakers:

Spencer Backman (Frankfurt)

Marta Casanellas (Barcelona)

Carlos D’Andrea (Barcelona)

Emanuele Delucchi (Freiburg)

Robin Evans (Oxford)

Kaie Kubjas (Aalto)

Anna Levina (Tübingen)

Marta Panizzut (TU Berlin)

Johannes Rauh (MPI Leipzig)

Cordian Riener (Tromsø)

Felipe Rincón (Queen Mary)

Kayvan Sadeghi (Cambridge)

Eduardo Sáenz de Cabezón (Logroño)

Anna Seigal (Berkeley)

Bernd Sturmfels (MPI Leipzig)

Timo de Wolff (TU Berlin)

Henry Wynn (LSE)

Piotr Zwiernik (Barcelona)

There is limited space available for participation in this conference. Please register your interest at the conference website by the 10th November 2018. Participants will be notified if they have been allocated a place at the conference by the 15th of November.

Supported by:

Heilbronn Institute of Mathematical Research, Institute of Mathematics, London Mathematical Society, University of Bristol

Continue Reading

Quantum Computing Theory in Practice

The past two years have seen rapid advances in building increasingly large-scale quantum computers. It is now widely expected that there will be a demonstration, within the coming months, of a device that cannot be simulated by any classical computer (so called ‘quantum computational supremacy’). The prospect of a relatively near-term device capable of a quantum advantage has sparked a huge amount of excitement both in academia and in industry. The conference will cover the central questions in this emerging field, focusing on how to use quantum computers to solve some of the grand challenges of our time, such as drug discovery or the development of energy-efficient industrial processes or new catalysts.

Topics will include quantum simulation, computational quantum chemistry and quantum algorithms for solving optimization problems. We will also invite speakers to talk about practical aspects of quantum programming and running experiments on current and imminent quantum computing hardware. The final theme will look to the future, with talks on scaling up quantum computers and new quantum algorithms.

The conference will include invited and contributed talks, together with a session bringing together end-users with quantum computing experts, and a poster session.

Please register here. Registration deadline: extended to 15 March 2019.

Conference participants may also be interested in the Bristol Quantum Information Technologies Workshop, to be held in Bristol the previous week (1-3 April). Registration deadline for that workshop is 18 March.

Keynote Speakers 

Iordanis Kerenidis (CNRS, IRIF, Univ Paris Diderot)
Hartmut Neven (Google)

Invited Speakers 

Ryan Babbush (Google)
Andrew Childs (University of Maryland)
Eleni Diamanti (CNRS, Univ Pierre et Marie Curie)
Aram Harrow (MIT)
Naomi Nickerson (PsiQuantum)
David Poulin (Université de Sherbrooke)
Marcus da Silva (Rigetti)
Kristan Temme (IBM)
Ronald de Wolf (CWI)

Accepted talks

Oscar Higgott, Daochen Wang and Steve Brierley. Variational Quantum Computation of Excited States
Sam McArdle, Xiao Yuan and Simon Benjamin. Error mitigated digital quantum simulation
Joran van Apeldoorn and Andras Gilyen. Quantum algorithms for zero-sum games
* Daniel Litinski. A Game of Surface Codes: Large-Scale Quantum Computing with Lattice Surgery
Joel Wallman and Steve Flammia. Reconstructing Pauli Error Channels
Sergey Bravyi, Dan Browne, Padraic Calpin, Earl Campbell, David Gosset and Mark Howard. Simulation of quantum circuits by low-rank stabilizer decompositions
* Andris Ambainis, Kaspars Balodis, Jānis Iraids, Martins Kokainis, Krišjānis Prūsis and Jevgēnijs Vihrovs. Quantum Speedups for Exponential-Time Dynamic Programming Algorithms

Juan Bermejo-Vega, Dominik Hangleiter, Martin Schwarz, Robert Raussendorf and Jens Eisert. Architectures for quantum simulation showing a quantum speedup

* Two accepted talks (starred) were selected to be presented as invited talks.


To be confirmed.


Please register here.


School of Chemistry, Lecture Theatre 2, University of Bristol, Cantock’s Close, Bristol, BS8 1TS.

The venue can be found using the University’s Google precinct map.


For planning purposes the venue is located within the main University precinct, postcode BS8 1TS. Information on local hotels and average prices can be found here. Alternatively you can find further information on other accommodation options by visiting the Visit Bristol website.


Please contact Francoise Blake regarding any administrative aspects of the conference.

Organising Committee

Steve Brierley (Riverlane)
Noah Linden (University of Bristol)
Ashley Montanaro (University of Bristol)

Programme Committee

Simon Benjamin (University of Oxford)
Dominic Berry (Macquarie University)
Steve Brierley (Riverlane)
Harry Buhrman (CWI / QuSoft)
Elizabeth Crosson (University of New Mexico)
Noah Linden (University of Bristol)
Ashley Montanaro (University of Bristol, chair)
Naomi Nickerson (PsiQuantum)

Local Organising Committee

Chris Cade
João Fernando Doriguello
Noah Linden
Lana Mineh
Ashley Montanaro
Alex Moylett
Stephen Piddock
Dominic Verdon

Call for submissions (deadline 11 January 2019)

Submissions are invited for contributed talks. Talks will be selected on the basis of scientific excellence; fit to the topic of the workshop; and balance of the programme.

Submissions should correspond to recent research contributions to quantum information and computation. The workshop will not publish proceedings, and work which has been, or will be, published elsewhere is welcome. Areas of interest include, but are not limited to:

  • Applications of quantum computers
  • Architectures for quantum computing
  • Quantum algorithms
  • Quantum compilation and circuit optimisation
  • Quantum error-correction and fault-tolerance
  • Simulation of quantum systems
  • Theory of near-term quantum computing
  • Verification of quantum devices

All submissions for talks must be made electronically through the online submission system EasyChair at

A submission should consist of a full paper corresponding to the work, including technical details. This manuscript may be from an on-line repository, such as the arXiv; however, a PDF copy of it must be uploaded. If your submission consists of multiple papers they should be merged into a single file.

We encourage all workshop attendees to present a poster. Poster details can be provided during registration.

Conflict of interest: Programme Committee members must declare a conflict of interest on submissions where this is relevant (such as ones where they, or a close associate, are a coauthor) so that they are not involved in the discussion of these papers.

Important dates

Submission deadline: 11 January 2019, 23:59 (Anywhere on Earth)
Notification: 8 February 2019
Registration deadline: extended to 15 March 2019


We are very grateful to our sponsors:







Continue Reading

Colloquium – Professor Tiina Roose, University of Southampton

Title: Multiscale image-based modelling in biology

In this talk I will describe a state of the art image based modelling in several seemingly different areas of biology. I show examples from biomedical (lymphatic, vascular and lung system) and agricultural problems of plant soil interaction. I will describe the workflow from imaging (X-ray CT, XRF, SEM-EDX, histology), image reconstruction, image segmentation, computation and how to utilize this work stream to synthesise new scientific knowledge. In particular I will also outline several challenges and bottlenecks in this process to hopefully encourage more mathematicians to get involved in the full pipeline.

Further information

The talk will be held in Tyndall Lecture Theatre, from 4pm – 5pm and will be followed by a drinks reception in the Maths common room.

The event is open to University of Bristol staff and students.

Continue Reading

Colloquium – Professor Bernd Sturmfels, University of California, Berkeley

Title: Varieties of signature tensors

We discuss recent developments in computational algebraic geometry that were motivated by the study of rough paths in stochastic analysis. Every path in a real vector space is encoded in a signature tensor whose entries are iterated integrals. As the path varies over a nice family we obtain an algebraic variety with interesting properties.

Further information

The talk will be held in Mott Lecture Theatre (G12), Physics, from 5pm – 6pm and will be followed by a drinks reception in the Maths common room.

The event is open to University of Bristol staff and students.

Continue Reading

Colloquium – Dr Miranda Mowbray, University of Bristol

Title: Predictive analytics: you can’t have it all

I will talk about limits to predictive analytics. The main application I’ll talk about is recidivism prediction – predicting whether a convicted criminal is likely to reoffend. However what I will say applies to predictive analytics more generally. As Alexandra Choldecova pointed out in the wake of a controversy about the COMPAS recidivism prediction algorithm, except in trivial cases, it is not mathematically possible to maximize the accuracy of recidivism prediction while meeting some fairness requirements for groups with different underlying recidivism rates. It is a policy choice whether or not to accept reduced accuracy, at least in the short term, in return for meeting fairness conditions. I will discuss this and some other limits to prediction that require policy choices. To make these choices, we need informed discussion and collaboration between techies, lawyers and policy makers. Just for fun, my slides will include 79 cats, a catbot, and Catwoman.

Further information

The talk will be held in Enderby Lecture Theatre (B16/B17), Physics, from 5pm – 6pm and will be followed by a drinks reception in the Maths common room.

The talk is open to all University of Bristol staff and students as well as the general public. We ask that all attendees please register in advance of the event.

Register to attend


Continue Reading