arXiv subjects

N. Shepherd-Barron

Publications and source records attributed to N. Shepherd-Barron.

2 recordsLinked to original sources

arXiv2019

An exceptional locus in the perfect compactification of $A_g$

The line bundle $12M-D$ on the perfect compactification $A_g^P$ is nef; we show here that in positive characteristic it is semi-ample and that in all characteristics its exceptional locus is the closure of the locus of abelian varieties with an elliptic factor.

math.AG↗

arXiv2016

The singularities of $A_g^P$

We complete the proof given earlier by one of us that the singularities of the perfect cone compactification $A_g^P$ of the coarse moduli space $A_g$ of principally polarized abelian $g$-folds are terminal if $g\ge 6$, and canonical if $g=5$.

math.AG↗