Degenerations of Abelian Differentials

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.

arXiv comment47 pages, 34 figures

References in corpus (4)

• Connected components of the moduli spaces of Abelian differentials with prescribed singularities
• Asymptotics of numbers of branched coverings of a torus and volumes of moduli spaces of holomorphic differentials
• Sum of Lyapunov exponents of the Hodge bundle with respect to the Teichmuller geodesic flow
• Invariant and stationary measures for the SL(2,R) action on Moduli space

Cited by in corpus (4)

• The Deligne-Mumford and the Incidence Variety Compactifications of the Strata of $\Omega {\mathcal{M}}_g$
• Teichmüller dynamics in the eyes of an algebraic geometer
• Effective divisors in ${\overline{\mathcal{M}}}_{g,n}$ from abelian differentials
• Spin and hyperelliptic structures of log twisted differentials