Finite Hilbert stability of (bi)canonical curves
Abstract
We prove that a generic canonically or bicanonically embedded smooth curve has semistable m-th Hilbert points for all m. We also prove that a generic bicanonically embedded smooth curve has stable m-th Hilbert points for all m \geq 3. In the canonical case, this is accomplished by proving finite Hilbert semistability of special singular curves with G_m-action, namely the canonically embedded balanced ribbon and the canonically embedded balanced double A_{2k+1}-curve. In the bicanonical case, we prove finite Hilbert stability of special hyperelliptic curves, namely Wiman curves. Finally, we give examples of canonically embedded smooth curves whose m-th Hilbert points are non-semistable for low values of m, but become semistable past a definite threshold. (This paper subsumes the previous submission and arXiv:1110.5960).
Keywords
Cite
@article{arxiv.1109.4986,
title = {Finite Hilbert stability of (bi)canonical curves},
author = {Jarod Alper and Maksym Fedorchuk and David Ishii Smyth},
journal= {arXiv preprint arXiv:1109.4986},
year = {2012}
}
Comments
To appear in Inventiones Mathematicae, 2012. The final publication is available at http://www.springerlink.com