Deligne's duality for de Rham realizations of 1-motives
arXiv:math/0506344
Abstract
We show that the pairing on de Rham realizations of 1-motives in "Theorie di Hodge III", IHES 44, can be defined over any base scheme and we prove that it gives rise to a perfect duality if one is working with a 1-motive and its Cartier dual. Furthermore we study universal extensions of 1-motives and their relation with -extensions.
arXiv comment21 pages. Last section rewritten. New proofs