Author Archives: TMS

Prof Timothy Gowers – A problem about triples of integers

Tomorrow’s talk will be given by Prof Timothy Gowers

Talk
Speaker: Prof Timothy Gowers
Title: A problem about triples of integers
Abstract: I shall talk about a problem that sounds like a reasonably easy IMO-style question, but which, rather surprisingly, is still unsolved. I shall talk about some non-trivial partial results, which are joint work with Jason Long, that fall well short of what is believed to be true.

The talk will take place at 8:30PM on Monday 13 March in the Winstanley Lecture Theatre. As usual there will be free port and juice served before the talk at 8:15PM. This talk is for members only, but there will be a chance to sign up for TMS life membership for £2.50.

Symposium 2017

This year’s Trinity Mathematical Society Symposium is running from 10:00 to 18:00 on Sunday 26nd February. We have talks by fellows and PhD students, ranging across all areas of mathematical research. The event is free and open to all; no particular specialist knowledge is assumed. There is no need to stay for the whole day – just drop in on talks you find interesting.

The program is:





12:15 – 14:00 Curve Fever: Curve Fever

12:15 – 13:15    BRUNCH




15:30 – 16:00    BREAK



19:45 –                Annual Dinner

(Made possible by the kind support of the Heilbronn Fund)

Prof Tim Pedley – Spherical squirmers

Tonight’s talk will be given by Prof Tim Pedley.

Talk
Speaker: Prof Tim Pedley
Title: Spherical squirmers – models for swimming micro-organisms: how a Tripos question led to a new field of research.
Abstract: In 1952, Sir James Lighthill (FT) introduced the simplest possible model of a swimming microorganism of finite size, intended as a model of a single-celled protozoan covered in beating cilia. The model consisted of a sphere, on the surface of which material points undergo small-amplitude oscillations. In 1971, Lighthill’s student, John Blake (FT), completed the calculations and in particular showed how to model the ‘metachronal’ wave patterns exhibited by beating cilia. In 1986 the speaker set a Part II Tripos question, to analyse an even simpler model consisting of a sphere whose surface moves tangentially with timeindependent velocity: a steady spherical squirmer. This has led to a substantial body of research on the optimisation pf the swimming and nutrient uptake of individual squirmers (Eric Lauga, FT), and on the hydrodynamic interactions between pairs of steady squirmers and their influence on self-diffusion in suspensions. The final topic describes measurements and modelling of metachronal waves in Volvox, the only truly spherical multicelled ‘organism’, culminating in the prediction of the mean swimming speed and angular velocity of free-swimming Volvox. The predictions are compared with experimental observations. [FT ≡ Fellow of Trinity]

The talk will take place at 8:30PM on Monday 20 February in the Winstanley Lecture Theatre. As usual there will be free port and juice served before the talk at 8:15PM. This talk is for members only, but there will be a chance to sign up for TMS life membership for £2.50.

Annual Dinner & Double Talk Week

We hope term is going really well and that the sheets aren’t getting you down!
Annual Dinner
This email is to let you know that our annual dinner is taking place after our Annual Symposium at 7:45pm, Sunday, 26th of February in the Old Kitchens. There will be a half hour reception with sparkling wine and apple juice. This year, to better accommodate people’s timetables, we’ll be staggering the ticket releases across the following times and dates:
5pm Monday 13/02
9pm Wednesday 15/02
Check your email at those times!

Double Talk Week
Also, we will have two talks this week. In addition to our usual Monday night talk, given by Dr Thomas Sauerwald, we will also have a joint talk with the Trinity College Science Society on Thursday evening, given by Dr Sander Dieleman. They both promise to be fantastic events, see the details below.Monday 13 February, 8:30PM
Speaker: Dr Thomas Sauerwald (Computer Lab)
Title: Multiple Random Walks
Abstract: Consider a simple random walk on a finite network. The expected time it takes for a single walk to visit all nodes is a well-studied quantity and has been computed for many topologies including paths, grids, random graphs and hypercubes. But how long does it take for two or more independently running random walks? This talk will explain why this may be an interesting question and present a few surprising results.

Thursday 16 February, 6:15PM
Speaker: Dr Sander Dieleman (Google DeepMind)
Title: Deep learning for music recommendation and generation
Abstract: The advent of deep learning has made it possible to extract high-level information from perceptual signals without having to specify manually and explicitly how to obtain it; instead, this can be learned from examples. This creates opportunities for automated content analysis of musical audio signals. In this talk, I will discuss how deep learning techniques can be used for audio-based music recommendation. I will also briefly discuss my ongoing work on music generation with WaveNet.

Both talks will take place in the Winstanley Lecture Theatre. As usual there will be free refreshments 15 minutes before the talk. The talk on Monday is for members only, but there will be a chance to sign up for TMS life membership for £2.50. The talk on Thursday is free for all.

Dr Julia Gog – Hunting for viral packaging signals

Tonight’s talk will be given by Dr Julia Gog.

Talk
Speaker: Dr Julia Gog
Title: Hunting for viral packaging signals
Abstract: Influenza has a genome split into several segments, and this complicates virus particle assembly as each particle must have one of each of the segments. This means that each of the RNA segments must contain some signal, and that this signal ought to be fairly conserved. Is this enough to go and hunt them down using mathematics? The answer turns out to be yes. However, this required some creativity in algorithm design, drawing inspiration from a number of apparently unrelated problems. This hack seems to work, but leaves some interesting mathematical problems. I’ll also briefly talk about some of the other problems in influenza and infectious disease that interest me, and general joys and challenges of being a mathematician trying to research biology.

The talk will take place at 8:30PM on Monday 6 February in the Winstanley Lecture Theatre. As usual there will be free port and juice served before the talk at 8:15PM. This talk is for members only, but there will be a chance to sign up for TMS life membership for £2.50.

Prof John Lister – Stretching, bending, twisting and coiling: how to build a fluid-mechanical sewing machine

This week’s talk will be given by Prof John Lister.

Talk
Speaker: Prof John Lister
Title: Stretching, bending, twisting and coiling: how to build a fluid-mechanical sewing machine
Abstract: Idlers at breakfast watching a stream of honey falling from a knife, may notice it buckle and coil as it reaches the toast. What happens if you move the toast (or the knife) steadily sideways? This talk will outline the mathematical description of the dynamics of a falling viscous thread, with possible diversions via chocolate fountains and Viennetta ice-cream.

The talk will take place at 8:30PM on Monday 30 January in the Winstanley Lecture Theatre. As usual there will be free port and juice served before the talk at 8:15PM. This talk is for members only, but there will be a chance to sign up for TMS life membership for £2.50.

Dr Tamara von Glehn – Logic in other universes

Welcome back to the TMS! The first talk of 2017 will be given by Dr Tamara von Glehn.

Talk
Speaker: Dr Tamara von Glehn
Title: Logic in other universes
Abstract: When doing ordinary mathematics, we don’t usually think too hard about exactly what logical rules are being used. But sometimes using for example the law of excluded middle or the axiom of choice can have unexpected consequences. In this talk I will explore some alternatives of classical logic. There are other ‘mathematical universes’, or toposes, in which different logical axioms can hold. I will introduce some of the structures used to express this logic, and describe what mathematics can look like inside a topos.

The talk will take place tonight at 8:30PM in the Winstanley Lecture Theatre. As usual there will be free port and juice served before the talk at 8:15PM. This talk is for members only, but there will be a chance to sign up for TMS life membership for £2.50.

Mathmo Call My Bluff

Come and celebrate Christmas with the TMS’ annual Call My Bluff event. Watch a Freshers’ Team take on a team drawn from the combined might of the rest of the university in a competition in which mathematical knowledge takes a second place to the ability to hold a good poker face. You can practise past questions online using our online game
As usual the event will take place on Monday 28th of November at 8:30PM in the Winstanley Lecture theatre.

Mathmo Call My Bluff
It has long been a tradition that every year, just before we all break up for Christmas, the TMS hosts a special mathematical adaptation of the cult BBC television quiz show, Call My Bluff. There are two teams of three, together with a host to keep things in order. The teams take it in turns to present three alternative definitions of an obscure mathematical word, only one of which is true—this is done by means of a dazzling, virtuoso display of wit and intellect, and occasionally completely unconvincing mathematics. The other team then has the task of deciding which one of the three alternatives is the correct one. If they guess correctly, they get a point; otherwise, their opponents get a point.

Cambridge Puzzle Hunt
We have a new puzzle Chess Puzzle. The answer to the puzzle is a word. You can submit your answer online at http://cph.soc.srcf.net/puzzles. Alternatively you can hand in your answer at the next TMS or TCSS talk. There will be prizes for some of the correct submissions. The deadline is Sunday 4th of December.

Prof Imre Leader – Cops and Robbers

Tonight at 20:30 Prof Imre Leader will give a talk to the TMS in the Winstanley Lecture Theatre.
As usual there will be port and juice served 15 minutes before the talk.

Talk
Speaker: Prof Imre Leader (DPMMS)
Title: Cops and Robbers
Abstract: Some cops are chasing a robber around a finite network. Moves alternate: the robber moves from where he is to an adjacent place, then all the cops move to adjacent places, and so on. For a given network, how many cops are needed to catch the robber?

Dr Perla Sousi – Percolation and Random Walks

On Monday 7th November Dr. Perla Sousi gave a talk to the TMS!

Talk
Speaker: Dr. Perla Sousi (Statslab)
Title: Percolation and Random Walks
Abstract: Consider the two dimensional lattice and keep every edge with probability p, independently over different edges. It is known that there exists a critical probability p_c so that for all p > p_c there exists a unique infinite connected component. But how well connected is this infinite cluster? One way to evaluate this is by examining the rate of spread of a simple random walk on the cluster.