The non semi-simple TQFT of the sphere with four punctures

Abstract

In this work, we compute the representation of the mapping class group of the sphere with $4$ punctures arising from the non semi-simple TQFT (constructed by Blanchet--Costantino--Geer--Patureau). We show that it is faithful. Lastly, we compare quantum representations of punctured spheres in general with those of braid groups.

19 pages Comments and remarks are welcome