A construction of an abelian variety with a given endomorphism algebra
Let be an abelian variety defined over a number field . In this short Note we give a characterization of the endomorphisms that preserve the height pairing associated to a polarization. We also give a functorial interpretation of this result.
For an Abelian Variety , the Künneth decomposition of the rational equivalence class of the diagonal gives rise to explicit formulas for the projectors associated to Beauville's decomposition (1) of the Chow ring , in terms of push-forward and pull-back of -multiplication. We obtain a few simplifications of such formulas, see theorem (4) below, and some related results, see proposition (9) below.
Si costruiscono famiglie di curve iperellittiche col —rango della varietà jacobiana uguale a zero. La costruzione sfrutta le proprietà elementari dell’operatore di Cartier e delle estensioni -cicliche dei corpi con la caratteristica maggiore di zero.