On subgroups of semi-abelian varieties defined by difference equations

We study the induced structure on definable groups in existentially closed difference fields. If G is a definable subgroup of a semi-abelian variety, orthogonal to every definable field, we show that G is stable and stably embedded; every definable subset of Gn is a Boolean combination of cosets of...

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Bibliografiska uppgifter
Huvudupphovsmän: Chatzidakis, Z, Hrushovski, E
Materialtyp: Journal article
Publicerad: American Mathematical Society 2016
Beskrivning
Sammanfattning:We study the induced structure on definable groups in existentially closed difference fields. If G is a definable subgroup of a semi-abelian variety, orthogonal to every definable field, we show that G is stable and stably embedded; every definable subset of Gn is a Boolean combination of cosets of definable subgroups of Gn, and Gn has at most countably many definable subgroups. This generalises to positive characteristic earlier results of the authors.