Elimination of generalised imaginaries and Galois cohomology
arXiv:1312.2273
Abstract
The objective of this article is to characterise elimination of finite generalised imaginaries (as defined by Hrushovski) in terms of group cohomology. As an application, I consider series of Zariski geometries constructed by Hrushovski and Zilber, and indicate how their non-definability in algebraically closed fields and other theories is connected to eliminability of certain generalised imaginaries.
arXiv commentsection 3 substantially simplified and rewritten