Invited speakers:

Raf Bocklandt (Amsterdam)
Julian Külshammer (Uppsala)
Alice Rizzardo (Liverpool)


In homological algebra and algebraic topology it is often natural to consider operations “up to homotopy”. However, treating homotopic maps as equal may have its own challenges, for instance concerning well-definedness and functoriality of various constructions. One natural attempt to remedy this is to explicitly record homotopies as part of the category. Iterating this idea (that is also recording homotopies between homotopies, and so on), one arrives at Stasheff’s definition of a stong homotopy structure (or A-infinity structure).

The aim of this summer school is two-fold: Firstly we will learn the definitions and basic properties of A-infinity structures. Then we will see where and how they can be useful for treating concrete problems.


Practical information

  • Arrival date: Sunday 9 June
  • Departure date: Friday 14 June or Saturday 15 June
  • Registration fee: 195 NOK
  • Price of stay at Sophus Lie Center (per person per day, meals included): double room 750 NOK, single room 825 NOK
Further practicalities: information about travel to and accomodation in Nordfjordeid.


To sign up for the summer school, contact one of the organizers as soon as possible.


For any questions, contact the organizers.


Sophus Lie summer schools in algebra committee

2019 summer school scientific organizers


  • Pure Mathematics in Norway
  • University of Bergen (UiB)
  • University of Oslo (UiO)
  • The Arctic University of Norway (UiT)
  • The Norwegian University of Science and Technology (NTNU)
  • University of Stavanger (UiS)