Pascal Lambrechts

The little $n$-dimensional disks operad is a fundamental object in algebraic topology and in some other fields. In particular it is a structure which encodes the natural multiplicative structure on iterated loop spaces, more generally multiplicative...

Abstract A famous result by Steven Smale states that we can turn the sphere inside-out through immersions: this is called the eversion of the sphere. We will explain this result and the strategy of its proof which is a "cut-and-paste" strategy quite...