2020 Workshop

Operads in deformation theory and homotopical algebra with Geoffroy Horel and Bruno Vallette


Lindlar, Germany


The sixth European Talbot workshop will take place in Germany after the summer of 2020. The goal is to bring together a group of 30-35 graduate students and post-docs to work on a focused topic under the guidance of two senior mentors.

Most of the talks will be given by the participants, with enough free time in the afternoon and evenings for further discussions and interaction. The character of the workshop is expository in nature, starting with the basic ideas and leading to a survey of the most recent developments in the field. Since all participants are staying together at a group house, jointly responsible for cooking and cleaning, we hope to create an informal and inspiring atmosphere.


The notion of an operad, which originates in homotopy theory with the recognition principle of loop spaces, nowadays plays a ubiquitous role in algebra, geometry, and topology. The algebraic calculus of operads developed over the past two decades provides us with seminal tools to manage and organise rich algebraic structures, such as algebras up to homotopy. The purpose of this workshop will be, first, to cover the main methods of this new operadic calculus, and then to study its most recent and striking application in deformation theory and homotopical algebra.

We plan to cover the following content:

    • Operadic calculus (Koszul duality theory, homotopy algebras).
    • Deformation theory (dg Lie algebra, gauge groups, integration of L_\infty-algebras).
    • Rational homotopy theory (new models with L_\infty-algebras and graph complexes, formality problems).
    • Relationship with Grothendieck-Teichmüller groups and Lie algebras (deformation theory, homotopy automorphism group of the little discs operad).


The application deadline has passed.


The local expenses for all participants will be covered by the workshop, in particular costs for accommodation and meals. Additional funds covering travel expenses might become available, however we strongly encourage participants to look for funding themselves.


For questions or suggestions, please send an email to the organisers at organisers@europeantalbot.org.

This workshop is organised by Bertram Arnold, Luci Bonatto, Jack Davies, and Alice Hedenlund, with coordinator (SFB contact) Georgios Raptis. We gratefully acknowledge funding and support from SPP 1786 and SFB 1085.