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Projective normality of abelian varieties with a line bundle of type 2 ,

Elena Rubei (1998)

Bollettino dell'Unione Matematica Italiana

Sia X una varietà abeliana e L un fibrato in rette ampio di tipo 2 , 2 d 2 , , 2 d g su X ; sia φ L l'applicazione associata a L . In questo lavoro si dimostra il seguente fatto: se d i 2 per qualsiasi i , L non è mai normalmente generato (quindi, se φ L è un embedding, φ L X non è proiettivamente normale); negli altri casi invece L è normalmente generato per X , c 1 L generico nello spazio dei moduli delle varietà abeliane polarizzate di tipo 2 , 2 d 2 , , 2 d g .

Prym Subvarieties P λ of Jacobians via Schur correspondences between curves

Yashonidhi Pandey (2010)

Annales de la faculté des sciences de Toulouse Mathématiques

Let π : Z X denote a Galois cover of smooth projective curves with Galois group W a Weyl group of a simple Lie group G . For a dominant weight λ , we consider the intermediate curve Y λ = Z / Stab ( λ ) . One defines a Prym variety P λ Jac ( Y λ ) and we denote by ϕ λ the restriction of the principal polarization of Jac ( Y λ ) upon P λ . For two dominant weights λ and μ , we construct a correspondence S λ μ on Y λ × Y μ and calculate the pull-back of ϕ μ by S λ μ in terms of ϕ λ .

Pseudo-abelian varieties

Burt Totaro (2013)

Annales scientifiques de l'École Normale Supérieure

Chevalley’s theorem states that every smooth connected algebraic group over a perfect field is an extension of an abelian variety by a smooth connected affine group. That fails when the base field is not perfect. We define a pseudo-abelian variety over an arbitrary field k to be a smooth connected k -group in which every smooth connected affine normal k -subgroup is trivial. This gives a new point of view on the classification of algebraic groups: every smooth connected group over a field is an extension...

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