Local-global properties of torsion points on three-dimensional abelian varieties

Let A be an abelian variety over a number field K, and let ℓ be a prime number. If A has a K-rational ℓ-torsion point, then for almost finite places [special characters omitted] of K, A has an ℓ-torsion point mod [special characters omitted]. Katz has shown that the converse is true if the dimension...

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Bibliographic Details
Main Author: Cullinan, John
Language:ENG
Published: ScholarWorks@UMass Amherst 2005
Subjects:
Online Access:https://scholarworks.umass.edu/dissertations/AAI3179867
Description
Summary:Let A be an abelian variety over a number field K, and let ℓ be a prime number. If A has a K-rational ℓ-torsion point, then for almost finite places [special characters omitted] of K, A has an ℓ-torsion point mod [special characters omitted]. Katz has shown that the converse is true if the dimension of A is less than three, and has exhibited specific counterexamples when A has dimension greater than or equal to three. Using the subgroup structure of the finite symplectic group, we classify those abelian threefolds which violate this local-global principle for ℓ-torsion points; some geometric realizations of these obstructions are provided.