Title: Quotients of absolute Galois groups which determine
the entire Galois cohomology
Authors: Sunil Chebolu, Ido Efrat, and Jan Minac
AMS Classification numbers: Primary 12G05; Secondary 12F10, 12E30
Abstract:
For prime power q=p^d and a field F containing a root of unity of order
q we show that the Galois cohomology ring H^*(G_F, Z/q) is determined by
a quotient G_F^{[3]} of the absolute Galois group G_F related to its
descending q-central sequence. Conversely, we show that G_F^{[3]} is
determined by the lower cohomology of G_F. This is used to give new examples of pro-p groups which do not occur as absolute Galois groups of fields.