English

Conformal blocks and rational normal curves

Algebraic Geometry 2015-01-13 v3

Abstract

We prove that the Chow quotient parametrizing configurations of n points in Pd\mathbb{P}^d which generically lie on a rational normal curve is isomorphic to M0,n\overline{M}_{0,n}, generalizing the well-known d=1d = 1 result of Kapranov. In particular, M0,n\overline{M}_{0,n} admits birational morphisms to all the corresponding geometric invariant theory (GIT) quotients. For symmetric linearizations the polarization on each GIT quotient pulls back to a divisor that spans the same extremal ray in the symmetric nef cone of M0,n\overline{M}_{0,n} as a conformal blocks line bundle. A symmetry in conformal blocks implies a duality of point-configurations that comes from Gale duality and generalizes a result of Goppa in algebraic coding theory. In a suitable sense, M0,2m\overline{M}_{0,2m} is fixed pointwise by the Gale transform when d=m1d=m-1 so stable curves correspond to self-associated configurations.

Keywords

Cite

@article{arxiv.1012.4835,
  title  = {Conformal blocks and rational normal curves},
  author = {Noah Giansiracusa},
  journal= {arXiv preprint arXiv:1012.4835},
  year   = {2015}
}

Comments

17 pages, 1 figure; published version

R2 v1 2026-06-21T17:02:48.855Z