All a b c d e f g h i j k l m n o p q r s t u v w x y z Other

Previous Page 10 Next

Displaying 181 – 200 of 262

Showing per page

Singularities of theta divisors and the geometry of 𝒜 5

Gavril Farkas, Samuele Grushevsky, Salvati R. Manni, Alessandro Verra (2014)

Journal of the European Mathematical Society

We study the codimension two locus H in 𝒜 g consisting of principally polarized abelian varieties whose theta divisor has a singularity that is not an ordinary double point. We compute the class [ H ] ∈ C H 2 ( 𝒜 g ) for every g . For g = 4 , this turns out to be the locus of Jacobians with a vanishing theta-null. For g = 5 , via the Prym map we show that H ⊂ 𝒜 5 has two components, both unirational, which we describe completely. We then determine the slope of the effective cone of 𝒜 5 ¯ and show that the component N 0 ' ¯ of the Andreotti-Mayer...

Some surfaces with maximal Picard number

Arnaud Beauville (2014)

Journal de l’École polytechnique — Mathématiques

For a smooth complex projective variety, the rank ρ of the Néron-Severi group is bounded by the Hodge number h 1 , 1 . Varieties with ρ = h 1 , 1 have interesting properties, but are rather sparse, particularly in dimension 2 . We discuss in this note a number of examples, in particular those constructed from curves with special Jacobians.

Sur les idéaux jacobiens des courbes planes

Jean-Pierre Henry (1977)

Annales de l'institut Fourier

Le ( n + 1 ) ème idéal jacobien itéré d’une courbe complexe algébroïde plane a même clôture intégrale que l’idéal jacobien d’un élément général du n ième idéal jacobien itéré. Ce résultat ramène pour les idéaux ci-dessus les calculs de multiplicité à des calculs de longueur.

Symmetric theta divisors of Klein surfaces

Christian Okonek, Andrei Teleman (2012)

Open Mathematics

This is a slightly expanded version of the talk given by the first author at the conference Instantons in complex geometry, at the Steklov Institute in Moscow. The purpose of this talk was to explain the algebraic results of our paper Abelian Yang-Mills theory on Real tori and Theta divisors of Klein surfaces. In this paper we compute determinant index bundles of certain families of Real Dirac type operators on Klein surfaces as elements in the corresponding Grothendieck group of Real line bundles...

Currently displaying 181 – 200 of 262