Brill-Noether loci and strata of differentials

Abstract

We prove that the projectivized strata of differentials are not contained in pointed Brill-Noether divisors, with only a few exceptions. For a generic element in a stratum of differentials, we show that many of the associated pointed Brill-Noether loci are of expected dimension. We use our results to study the Auel-Haburcak Conjecture: We obtain new non-containments between maximal Brill-Noether loci in $\mathcal{M}_g$. Our results regarding quadratic differentials imply that the quadratic strata in genus $6$ are uniruled.