3
$\begingroup$

If I have two schemes $X$ and $Y$, which are such that my question makes sense (I guess, they should be abelian varieties over a field $k$, so assume this).

Then I have often read, but nowhere found a proper definition, the notion of a $\mathbb{G}_{m}$- biextension of $X \times Y$.

I would be very glad if someone could explain this notion properly to me, maybe with an example (I think one often speaks of the "Poincaré-Biextension).

  • 0
    Have you tried http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.366.5265&rep=rep1&type=pdf ? – 2016-05-13

1 Answers 1