Summands of theta divisors on Jacobians
Algebraic Geometry
2020-07-15 v3 Representation Theory
Abstract
We show that the only summands of theta divisors on Jacobians of curves and on intermediate Jacobians of cubic threefolds are the obvious powers of the curve and the Fano surface of lines on the threefold. The proof uses the decomposition theorem for perverse sheaves, a bit of representation theory and a computation of characteristic cycles for Brill-Noether sheaves.
Keywords
Cite
@article{arxiv.1811.01072,
title = {Summands of theta divisors on Jacobians},
author = {Thomas Krämer},
journal= {arXiv preprint arXiv:1811.01072},
year = {2020}
}
Comments
references updated, background on fiber functors and lambda rings added, proof of 2.5 made self-contained