The final CIRCA seminar of the semester will be on 13th April, at 1pm in Theatre C of Maths.

Ian Gent will speak on A Dream Model for Black Hole

Murray Whyte will speak on Irredundant monoid presentations

All welcome

The final CIRCA seminar of the semester will be on 13th April, at 1pm in Theatre C of Maths.

Ian Gent will speak on A Dream Model for Black Hole

Murray Whyte will speak on Irredundant monoid presentations

All welcome

The final two CIRCA seminars of term will be

Thursday 17th November: Finn Smith and Jacob Beaddie

Thursday 24th November: Michael Young and Peter Cameron. Note the unusual date for this one, and also that it will be in Purdie C rather than Maths.

The seminars for Autumn 2022 will be held on Thursdays of even weeks at 1pm in Theatre B of Maths. The schedule at present is:

September 22nd: Colva Roney-Dougal and Chris Jefferson

October 6th: Ruth Hoffman and Alan Logan

October 20th: Saul Freedman and Ozgur Akgun

November 3rd: Jendrik Brachter (TU Darmstadt)

November 17th: TBA

December 1st: Michael Young and Peter Cameron

There will be a seminar on Wednesday February 7th, 2018 at 1pm in Lecture Theatre D: Peter Cameron will speak on Reed–Muller codes and Thomas’ conjecture.

Abstract: A countable first-order structure is countably categorical if its automorphism group has only finitely many orbits on n-tuples of points of the structure for all n. (Homogeneous structures over finite relational languages provide examples.) For countably categorical structures, we can regard a reduct of the structure as a closed overgroup of its automorphism group. Simon Thomas showed that the famous countable random graph has just five reducts, and conjectured that any countable homogeneous structure has only finitely many reducts. Many special cases have been worked out but there is no sign of a general proof yet. In order to test the limits of the conjecture, Bertalan Bodor, Csaba Szabo and I showed that a vector space over GF(2) of countable dimension with a distinguished non-zero vector has infinitely many reducts. The proof can most easily be seen using an infinite generalisation of the binary Reed–Muller codes.