248 research outputs found
Existentially closed fields with G-derivations
We prove that the theories of fields with Hasse-Schmidt derivations
corresponding to actions of formal groups admit model companions. We also give
geometric axiomatizations of these model companions.Comment: In version 2: new proof of (the current) Proposition 3.3
Imaginaries in separably closed valued fields
We show that separably closed valued fields of finite imperfection degree
(either with lambda-functions or commuting Hasse derivations) eliminate
imaginaries in the geometric language. We then use this classification of
interpretable sets to study stably dominated types in those structures. We show
that separably closed valued fields of finite imperfection degree are
metastable and that the space of stably dominated types is strict
pro-definable
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