1. Statistical Laboratory, University of Cambridge , Cambridge, Cambridgeshire , UK
2. Ecole Normale Supérieure , , , Paris , France
3. PSL Research University , , , Paris , France
4. INRIA , , , Paris , France
5. Department of Statistics , , London, London , UK
6. London School of Economics and Political Science , , London, London , UK
7. Department of Statistical Science , , London , UK
8. University College London , , London , UK
9. Statistical Laboratory, University of Cambridge , Cambridge ,, Cambridgeshire , UK