The Brauer-Manin obstruction for sections of the fundamental group
arXiv:0910.5009
Abstract
We establish Grothendieck's section conjecture for an open subset of the Reichardt-Lind curve, and introduce the notion of a Brauer-Manin obstruction for sections of the fundamental group extension.
32 pages, with an appendix containing a letter from P. Deligne to D. Thakur