The INI has a new website!

This is a legacy webpage. Please visit the new site to ensure you are seeing up to date information.

Skip to content



Introduction to E_n-operads and little discs operads (mini-course)

Fresse, B (Université Lille 1)
Tuesday 05 March 2013, 14:00-15:15

Seminar Room 2, Newton Institute Gatehouse


The little n-discs operads, where n = 1,2,...,infinity, are used to define a hierarchy of homotopy commutative structures, from fully associative but non-commutative (n=1) up to fully associative and commutative (n=infinity).

In the construction of such homotopy commutative structures, we generally have to deal with operads which are just weakly-equivalent to the little n-discs, and the name of an E_n-operad has been introduced to refer to this notion. In this first lecture, I will give an introduction to E_n-operads and their applications. I will notably report on the following significant issues: formality, Koszul duality, and recognition theorems.

General reference:B. Fresse, "Homotopy of operads and Grothendieck-Teichmüller Groups". Book project. First volume available on the web-page ""


[pdf ]


The video for this talk should appear here if JavaScript is enabled.
If it doesn't, something may have gone wrong with our embedded player.
We'll get it fixed as soon as possible.

Back to top ∧