An alternative proof of a theorem by D. Witte
B. Deroin

We will give an alternative proof of the theorem by D. Witte, stating that an amenable left orderable group is locally indicable, i.e. every finitely generated subgroup has a non trivial morphism to the integers. We will then explain some properties of symmetric random walks on left orderable groups, and related problems. This latter part is a joint work with V. Kleptsyn, A. Navas and K. Parwani.