A special day of the seminar of the Algebraic Topology team will be devoted to the topic of Higher Structures with talks of the members of the PhD jury of the thesis of Daniel Robert-Nicoud (June 22).

Schedule:- 10-11am: Alexander Berglund (University of Stockholm)
- 11.30-12.30am: Joana Cirici (University of Barcelona)
- 2-3pm: Thomas Willwacher (ETH Zürich)
- 3.30-4.30pm: Giovanni Felder (ETH Zürich)
## Location:
The talks will take place at Amphitheater Fermat of the Institute Galilée (Villetaneuse Campus). Indications here (French) and there (English) |

- Alexander Berglund: ``Differential graded Lie algebra models for diffeomorphism groups''

By combining earlier work of Madsen and myself with classical work on pseudo-isotopy theory and algebraic K-theory of spaces, due to Waldhausen, Burghelea--Lashof, Dwyer--Hsiang--Staffeldt and others, we construct a dg Lie algebra that encodes the rational homotopy type of BDiff(M) in the so-called pseudo-isotopy stable range.

- Joana Cirici: ``Sheaves of E-infinity algebras and applications to algebraic varieties and singular spaces''

- Thomas Willwacher: ``Little disks operads and rational Goodwillie-Weiss calculus''

I report on joint work with Victor Turchin and Benoit Fresse, in which we (mostly) settle the rational homotopy theory of the little n-disks operads, by showing that they are intrinsically formal for n>=3, and by computing the rational homotopy type of the function spaces between these objects.

As an application we obtain complete rational invariants of long knots in codimension >=3.

- Giovanni Felder: ``Gauge theory partition functions, representation schemes and random matrices''