Tom Leinster

 

Publications

 

My book, Higher Operads, Higher Categories, is available free on the web and published in traditional form by Cambridge University Press. Summary and further information.

Here are my papers, grouped by subject. Within each subject, the most recent are listed first. You can also read an old overview of my papers up to about 2003. Cardinality and Euler characteristic: A maximum entropy theorem with applications to the measurement of biodiversity, arXiv:0910.0906, 27 pages, 2009 On the asymptotic magnitude of subsets of Euclidean space (with Simon Willerton), arXiv:0908.1582, 20 pages, 2009, submitted; discussion The Euler characteristic of a category as the sum of a divergent series (with Clemens Berger), arXiv:0707.0835, 11 pages, 2007; also Homology, Homotopy and Applications 10 (2008), 41–51; discussion The Euler characteristic of a category, math.CT/0610260, 2006; also Documenta Mathematica 13 (2008), 21–49; nice description here and discussion here and here Self-similarity and recursion: General self-similarity: an overview, math.DS/0411343, 10 pages, 2004; also in Real and Complex Singularities (Proceedings of the Australian-Japanese Workshop, Sydney, 2005), World Scientific (2007) A general theory of self-similarity II: recognition, math.DS/0411345, 28 pages, 2004, submitted A general theory of self-similarity I, math.DS/0411344, 49 pages, 2004, submitted Objects of categories as complex numbers (with Marcelo Fiore), math.CT/0212377, 13 pages, 2002; also Advances in Mathematics 190 (2005), 264-277 An objective representation of the Gaussian integers (with Marcelo Fiore), math.RA/0211454, 6 pages, 2002; also Journal of Symbolic Computation 37 (2004), no. 6, 707-716 Category theory in algebra: A simple description of Thompson's group F (with Marcelo Fiore), math.GR/0508617, 14 pages, 2005, accepted by Semigroup Forum Are operads algebraic theories?, math.CT/0404016, 2004; also Bulletin of the London Mathematical Society 38 (2006), no. 2, 233-238 Higher-dimensional category theory: A survey of definitions of n-category, math.CT/0107188, 67 pages, 2001; also Theory and Applications of Categories 10 (2002), no. 1, 1-70 Topology and higher-dimensional category theory: the rough idea, math.CT/0106240, 15 pages, 2001 Operads in higher-dimensional category theory (PhD thesis), math.CT/0011106, viii + 127 pages, 2000; also Theory and Applications of Categories 12 (2004), no. 3, 73-194 Generalized enrichment of categories, math.CT/0204279, 18 pages, 1999; also Journal of Pure and Applied Algebra 168 (2002), no. 2-3, 391-406 fc-multicategories, math.CT/9903004, 8 pages, 1999 Generalized enrichment for categories and multicategories, math.CT/9901139, 79 pages, 1999 Basic bicategories, math.CT/9810017, 11 pages, 1998 Structures in higher-dimensional category theory, math.CT/0109021, 81 pages, 1998 General operads and multicategories, math.CT/9810053, 35 pages, 1997 (Polished versions of most of the material in these unpublished papers can be found in my book.) Homotopy algebra: Homotopy algebras for operads, math.QA/0002180, 101 pages, 2000 Up-to-homotopy monoids, math.QA/9912084, 8 pages, 1999 Miscellaneous: Perfect numbers and groups, math.GR/0104012, 12 pages, 1996ish; associated Sloane's integer sequence The references above are to the electronic mathematics archive. For faster downloading, or if the links above aren't working, try a mirror site near you: Australia, Brazil, China, France, Germany, India, Russia, Spain, UK.

 

Talks

 

Here are slides and notes from some talks, grouped by subject. Within each subject, the most recent are listed first. Cardinality and Euler characteristic: Size (for a pure-mathematical audience, mostly model theorists) Counting, measure and metrics (for a general mathematical audience) How to measure almost anything (for a general scientific audience) The cardinality of a metric space (shorter) The cardinality of a metric space (longer) New perspectives on Euler characteristic (for a general mathematical audience) The Euler characteristic of a category (for category theorists) Another look at Euler characteristic (for a general pure-mathematical audience) Self-similarity and recursion: Terminal coalgebras via modules Coalgebraic topology Periodicity of spaces of walks Jónsson-Tarski toposes Self-similarity and recursion A universal Banach space Category theory in algebra: The Thompson groups Nerves of algebras (see also this discussion) Higher-dimensional category theory: Introduction to higher (especially globular) operads A survey of the theory of bicategories Operads (90-minute tutorial) Higher-dimensional algebra (for politicians) Mathematics in general: The power of abstract thinking (for prospective Ph.D. students) The peculiar traits of human mathematics Other talk-related things: The Scottish Category Theory Seminar Extremely short introduction to Beamer (a package that allows you to prepare pdf talk slides in Latex) Conference in celebration of the 60th birthday of my PhD supervisor, Martin Hyland The 2008 Rankin Lectures, given in Glasgow by John Baez Tips on giving talks (ps, pdf) The 83rd Peripatetic Seminar on Sheaves and Logic (held here in 2006); includes some notes from the talks Category theory seminars in Cambridge, 1996-2002

 

Notes

 

I'm one of the hosts of The n-Category Café, a research blog on mathematics, physics and philosophy. Here are my posts (most recent first): An adventure in analysis Asymptotics of the magnitude of metric spaces Entropy, diversity and cardinality (part 2) Entropy, diversity and cardinality (part 1) The cardinality of a metric space How I learned to love the nerve construction On Linear Algebra Done Right Here are a couple of my comments at the n-Category Café: A short explanation of the Central Limit Theorem and how to view it as a result about maximum entropy Informal introduction to classifying toposes And here are some odds and ends: An interview with me in the December 2008 issue of The Reasoner, largely about higher categories Doing without diagrams: how to take a proof that uses elements, utter some magic words, and conclude that it's valid in any category A proof that sheaves do not belong to algebraic geometry My favourite proof of the Fundamental Theorem of Algebra: argument learned from Graeme Segal and notes extracted from a course I taught

 

Teaching

 

Glasgow M.Sci. Category Theory 2007-8 Glasgow 4H Galois Theory 2005-6 Glasgow Category Theory 2004 Common errors in first year undergraduate work Cambridge Part III Category Theory 2000 Cambridge Part IA/IB Linear Maths: some notes on the minimal polynomial and Jordan canonical form

 

Email: 'T.Leinster', followed by the at sign, followed by 'maths.gla.ac.uk' This page was last changed on 4 November 2009. Photo.