In Part I of this series of posts, I introduced the sporadic groups, finite groups of symmetries which aren’t the symmetries of any obvious categories of shapes. The sporadic groups in turn are classified into the Happy Family, headed by the Monster group, and the Pariahs. In Part II, I discussed Monstrous Moonshine, the connection between the Monster group and a type of function called a modular form. This in turn ties the Monster group, and with it the Happy Family, to elliptic curves, Fermat’s Last Theorem, and string theory, among other things. But until 2017, the Pariah groups remained stubbornly outside these connections.
You're reading: Irregulars
- Mike Bassett, England Manager
Review: The Maths Behind… by Colin Beveridge
Ed Rochead sent us this review of Aperiodipal Colin Beveridge’s latest pop maths book.
This book is written to answer the question ‘when would you ever use maths in everyday life?’ It therefore focuses on applied maths, across a surprisingly wide breadth of applications. The book is organised into sections such as ‘the human world’, ‘the natural world’, ‘getting around’ and ‘the everyday’. Within each section there are approximately ten topics, for which the maths behind some facet of ‘everyday life’ is explained, with cheerful colour graphics and not shying away from using an equation where necessary.
When numbers aren’t neutral: the hidden politics of budget calculators
The day after last week’s budget, I logged onto the BBC News website and clicked on their budget calculator to find out if I was a winner or a loser. The questions are pretty simple: first off, it asks how much you drink, smoke and drive, and then it asks how much you earn, plus a few bits and bobs to cover technicalities. Then, it spits out an answer: did Phil leave you feeling flush, was it more of a hammering at the hands of Hammond? I came away £8 a month better off…and significantly angrier than I expected.
“Pariah Moonshine” Part II: For Whom the Moon Shines
This post is part of a series of posts by guest author Joshua Holden.
I ended Part I with the observation that the Monster group was connected with the symmetries of a group sitting in 196883-dimensional space, whereas the number 196884 appeared as part of a function used in number theory, the study of the properties of whole numbers. In particular, a mathematician named John McKay noticed the number as one of the coefficients of a modular form.
“Pariah Moonshine” Part I: The Happy Family and the Pariah Groups
Being a mathematician, I often get asked if I’m good at calculating tips. I’m not. In fact, mathematicians study lots of other things besides numbers. As most people know, if they stop to think about it, one of the other things mathematicians study is shapes. Some of us are especially interested in the symmetries of those shapes, and a few of us are interested in both numbers and symmetries.
Footballs on road signs: an international overview
I’m an old fashioned manager, I write the team down on the back of a fag packet and I play a simple 4-4-2.
I’m very much like Mike Bassett: I like standing on the terraces, I like full-backs whose main skill is kicking wingers into the ad hoardings, and – most of all – I like geometrically correct footballs.
Stirling’s numbers in a nutshell
This is a guest post by researcher Audace Dossou-Olory of Stellenbosch University, South Africa.
In assignment problems, one wants to find an optimal and efficient way to assign objects of a given set to objects of another given set. An assignment can be regarded as a bijective map $\pi$ between two finite sets $E$ and $F$ of $n\geq 1$ elements. By identifying the sets $E$ and $F$ with $\{1,2,\ldots, n\}$, we can represent an assignment by a permutation.