GGSE in Oxford, Friday 27th May 2016

A reminder from Henry Wilton:

Dear all,

A quick reminder about next week’s GGSE in Oxford.  First, we’re delighted to announce that Jim Howie will also talk.  The programme is as follows.

Location: Lecture Theatre 6, Andrew Wiles Building, Oxford

2pm Jim Howie (Heriot—Watt): 1-relator quotients of free products
3.15pm: Ashot Minasyan (Southampton): Conjugacy separability of non-positively curved groups
4.30pm: Henry Wilton (Cambridge): Essential surfaces in graphs

NOTE the later-than-usual start time.

As usual, further information, including times, locations and abstracts, will be available on the website: .

And finally, if you're a parent who may have difficulty attending the meeting, please don't forget about LMS childcare grants:

We’re looking forward to seeing you there!

Best wishes,


Paul Baum mini course on the Atiyah Singer index theorem

Prof. Paul Baum, Evan Pugh Professor of Mathematics at Penn State, will be delivering a short course on the Atiyah-Singer index theorem, aimed at a general mathematical audience. If you want to read something about the theorem in advance there is a very short article about it on the Abel Prize website:

Details below:
MONDAY 23rd May, 2-3PM, Lecture Theatre 4A, Building 54
The Dirac operator of R^n will be defined. This is a first order elliptic differential operator with constant coefficients.
Next, the class of differentiable manifolds which come equipped with an order one differential operator which at the symbol level is locally isomorphic to the Dirac operator of R^n will be considered. These are the Spin-c manifolds.
Spin-c is slightly stronger than oriented, so Spin-c can be viewed as "oriented plus epsilon". Most of the oriented manifolds that occur in practice are Spin-c. The Dirac operator of a closed Spin-c manifold is the basic example for the Hirzebruch-Riemann-Roch theorem and the Atiyah-Singer index theorem.

TUESDAY 24th May, 2-3PM, LECTURE THEATRE 4A, Building 54
This is an expository talk about the Atiyah-Singer index theorem. Some low dimensional examples of the theorem will be considered. The Dirac special case of the theorem will be proved, with the proof based on Bott periodicity. The proof will be outlined that the Dirac special case implies the full theorem.

Beyond Hyperbolicity, Cambridge 20-24th June 2016

From the conference web page at

The aim of this conference is to look closely at various generalizations of Gromov hyperbolicity that are currently of significant interest. We particularly want to compare the different definitions, and put them into conversation with one another. Examples include: acylindrical hyperbolicity, hierarchical hyperbolicity, coarse median structures (in the sense of Bowditch), (bi)automatic groups, semi-hyperbolic groups, and asymptotically CAT(0) groups. Various generalizations of the idea of Gromov boundary are also relevant (contracting, Morse, and HHS boundaries, etc). Certain classes of examples are also of special interest: mapping class groups, Out(F_n), RAAGs.

Paul Baum visit

Paul Baum will be visiting the non-commutative geometry group from 22nd to 25th May. He has offered two expository talks (one on K-theory and one on the Atiyah-Singer index theorem) so do let me know if you have a preference.

Roger Plymen visiting

Roger will be here from 25th-28th April.