Abstract
Consider degenerations of Abelian differentials with prescribed number and multiplicity of zeros and poles. Motivated by the theory of limit linear series, we define twisted canonical divisors on pointed nodal curves to study degenerate differentials, give dimension bounds for their moduli spaces, and establish smoothability criteria. As applications, we show that the spin parity of holomorphic and meromorphic differentials extends to distinguish twisted canonical divisors in the locus of stable pointed curves of pseudocompact type. We also justify whether zeros and poles on general curves in a stratum of differentials can be Weierstrass points. Moreover, we classify twisted canonical divisors on curves with at most two nodes in the minimal stratum in genus three. Our techniques combine algebraic geometry and flat geometry. Their interplay is a main flavor of the paper.
Funding Statement
During the preparation of this article the author was partially supported by the NSF CAREER Award DMS-1350396.
Citation
Dawei Chen. "Degenerations of Abelian differentials." J. Differential Geom. 107 (3) 395 - 453, November 2017. https://doi.org/10.4310/jdg/1508551222
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