Résumé
We consider the geometric quantisation of Chern-Simons theory for closed genus-one surfaces and semisimple complex algebraic groups. First we introduce the natural complexified analogue of the Hitchin connection in Kahler quantisation, with polarisations coming from the nonabelian Hodge hyper-Kahler geometry of the moduli spaces of flat connections, thereby complementing the real -polarised approach of Witten. Then we consider the connection of Witten, and we identify it with the complexified Hitchin connection using a version of the Bargmann transform on polarised sections over the moduli spaces.