Triple Massey products and absolute Galois groups
arXiv:1412.7265
Abstract
Let be a prime number, a field containing a root of unity of order , and the absolute Galois group. Extending results of Hopkins, Wickelgren, Minac and Tan, we prove that the triple Massey product contains whenever it is nonempty. This gives a new restriction on the possible profinite group structure of .
A first version of this paper, by the second-named author, was earlier posted as arXiv:1411.4146. The current version gives a purely group-cohomological proof of the main result. To appear in the Journal of the European Mathematical Society