2016-12-30: | The paper Decomposition spaces in combinatorics with Imma Gálvez and Andy Tonks is now available. It was originally Section 5 of the long manuscript arXiv:1404.3202. |
2016-12-01: | Short paper (14pp) available: Cospan construction of the graph category of Borisov and Manin, dedicated to Nils Baas for his 70th birthday. Feedback is most welcome. |
2016-10-28: | Michael Batanin, Ralph Kaufmann and Martin Markl have founded a new journal, Higher Structures. I am proud to be a member of the editorial board, and I welcome strong submissions on higher categories and operads. (Instructions for authors can be found on the journal web site.) |
2016-10-13: | Tom Leinster and I join forces to give a BGSMath graduate course on Category Theory in January 2017. |
2016-09-13: | New joint paper with Mark Weber available: Faà di Bruno for operads and internal algebras. Feedback is most welcome. |
2016-03-01: | Short paper (4pp) with David Spivak available: Homotopy composition of cospans. Feedback is most welcome. |
2016-02-21: | The paper Homotopy linear algebra with Imma Gálvez and Andy Tonks is now available. It was originally the appendix of arXiv:1404.3202. |
2016-01-01: | The long manuscript arXiv:1404.3202 with Imma Gálvez and Andy Tonks (182pp) has been split into six papers. The first three are now on the arXiv: |
2015-12-10: | My paper "Polynomial functors and combinatorial Dyson-Schwinger equations" is available. An expository companion paper, "Combinatorial Dyson-Schwinger equations and inductive data types", is also available. Feedback is most welcome on both papers. |
2015-11-01: | My joint work with Michael Batanin and Mark Weber, "Regular patterns, substitudes, Feynman categories and operads", is now on the arXiv. Feedback is most welcome. |
2015-09-07: | This year's Barcelona Topology Workshop will take place on November 27--28, at the CRM in Barcelona. More info will follow soon. |
2014-11-13: | My short paper "Perturbative renormalisation for not-quite-connected bialgebras" is now on the arXiv. Comments are most welcome. |
2014-07-15: | My paper "Graphs, hypergraphs, and properads"
is available.
Comments are very welcome. |
2014-04-14: | My long paper with Imma Gálvez and Andy Tonks, "Decomposition spaces, incidence algebras and Möbius inversion" is finally available. Comments are very welcome. |
2013-05-08: | My paper with Wolfgang Pitsch, "Hochster duality in derived categories and point-free reconstruction of schemes" is now available. Comments are very welcome. |
2013-04-04: | New grant info for the CRM conference "Type Theory, Homotopy Theory and Univalent Foundations", September 23-27, 2013. |
2013-01-26: | "String diagrams, the number 5, and the moons of Jupiter" - a tribute to "This Weeks' Finds". |
2012-12-09: | We'll have a conference at the CRM entitled "Type Theory, Homotopy Theory and Univalent Foundations", September 23-27, 2013. |
2012-08-09: | My paper with David Gepner, "Univalence in locally cartesian closed ∞-categories" is now available. Comments are very welcome. |
2012-07-28: | The paper "Groupoids and Faà di Bruno formulae for Green functions in bialgebras of trees" joint with Imma Gálvez and Andy Tonks is now available. Comments are very welcome. |
2011-09-28: | A first version of the paper "Categorification of Hopf algebras of rooted trees" is now available. Comments are very welcome. |
2011-09-08: | Eric Finster from the EPFL has created an online interactive opetope explorer! |
2011-06-01: | "Double adjunctions and free monads", joint work with Tom Fiore and Nicola Gambino, is now available. It is the second part of a trilogy on double categories. |
2011-03-31: | On my Math page, the stuff is now organised after subject. Some further reorganisation of pages. |
2010-06-07: | "Monads in double categories", joint work with Tom Fiore and Nicola Gambino, is now available. It is the first part of a trilogy on double categories... |
2010-05-25: | "Local fibered right adjoints are polynomial", joint work with my father, is now available. |
2010-01-04: | New office: C1/322, new telephone number: 4547. |
2009-08-23: | I have posted some photos—mostly people—from the Category Theory Workshop in Santa Marta, Colombia. |
2009-08-19: | A short paper with André Joyal, Feynman graphs, and nerve theorem for compact symmetric multicategories (extended abstract), corresponding to my conference talks in Pisa, Oxford, and Luminy, is now available (also from the arXiv). A more detailed account of this theory will follow. |
2009-08-06: | Substantial revision of my messy manuscript Notes on
polynomial functors
(420pp. -- still just a heap of annotations.) Comments are very welcome. |
2009-07-27: | My paper Coherence for weak units with André Joyal is finally available. (It is a companion paper to our paper Weak units and homotopy 3-types, and we ought to have finished it four years ago.) Comments are very welcome. |
2009-06-07: | My paper Polynomial functors and polynomial monads with Nicola Gambino is finally available. Comments are very welcome. |
2008-07-13: | My paper Polynomial functors and trees is now available. Comments are very welcome. |
2007-06-07: | My paper Polynomial functors and opetopes joint with André Joyal, Michael Batanin, and Jean-François Mascari is finally available. The linked page also has download of opetope scripts, and some examples and pictures. |
2007-05-24: | Substantial updates to Notes on
polynomial functors. Still a very messy manuscript. |
2006-11-09: | Another substantial update to Notes on polynomial functors. |
2006-10-24: | Substantial update to Notes on polynomial functors. |
2007-02-28: | First erratum to my book with Israel Vainsencher: An invitation to quantum cohomology. |
2006-08-18: | The "twelve slidings with sixteen tiles" computation in my Note on commutativity in double semigroups and two-fold monidal categories is now available as an animation. |
2006-06-26: | It is now official that we will have a
CRM
special year 2007-2008 on Homotopy Theory and Higher Categories. More details to follow. |
2006-06-02: | The Frobenius-algebra-and-2D-TQFT page updated with some very interesting historical remarks due to Aurelio Carboni and Bob Walters. |
2006-02-05: | My StreetFest paper with André Joyal, Weak units and homotopy 3-types is now available. |
2006-01-14: | Notes on polynomial functors revised and expanded (only Section 1). Shorter manuscript Polynomial functors, negative sets, and moduli of punctured Riemann spheres available too, from the same page. |
2006-01-10: | There is now a page for old news -- oh my, this site changes so quickly I can hardly follow it! |
2006-01-10: | There is now a NEWS banner on my front page. |