Model Theory and Algebraic Geometry : An introduction to E. Hrushovski's proof of the geometric Mordell-Lang conjecture

Bouscaren, Elisabeth

ISBN 10: 3540648631 / ISBN 13: 9783540648635

Editore: Springer 1999-10, 1999

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Codice articolo 6666-IUK-9783540648635

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Titolo: Model Theory and Algebraic Geometry : An ...

Casa editrice: Springer 1999-10

Data di pubblicazione: 1999

Legatura: PF

Condizione: New

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Riassunto:

Introduction Model theorists have often joked in recent years that the part of mathemat­ ical logic known as "pure model theory" (or stability theory), as opposed to the older and more traditional "model theory applied to algebra" , turns out to have more and more to do with other subjects ofmathematics and to yield gen­ uine applications to combinatorial geometry, differential algebra and algebraic geometry. We illustrate this by presenting the very striking application to diophantine geometry due to Ehud Hrushovski: using model theory, he has given the first proof valid in all characteristics of the "Mordell-Lang conjecture for function fields" (The Mordell-Lang conjecture for function fields, Journal AMS 9 (1996), 667-690). More recently he has also given a new (model theoretic) proof of the Manin-Mumford conjecture for semi-abelian varieties over a number field. His proofyields the first effective bound for the cardinality ofthe finite sets involved (The Manin-Mumford conjecture, preprint). There have been previous instances of applications of model theory to alge­ bra or number theory, but these appl~cations had in common the feature that their proofs used a lot of algebra (or number theory) but only very basic tools and results from the model theory side: compactness, first-order definability, elementary equivalence...

Contenuti:

to model theory.- to stability theory and Morley rank.- Omega-stable groups.- Model theory of algebraically closed fields.- to abelian varieties and the Mordell-Lang conjecture.- The model-theoretic content of Lang’s conjecture.- Zariski geometries.- Differentially closed fields.- Separably closed fields.- Proof of the Mordell-Lang conjecture for function fields.- Proof of Manin’s theorem by reduction to positive characteristic.