English

Moduli spaces of weighted pointed stable rational curves via GIT

Algebraic Geometry 2010-03-29 v2

Abstract

We construct the Mumford-Knudsen space of n pointed stable rational curves by a sequence of explicit blow-ups from the GIT quotient (P^1)^n//SL(2) with respect to the symmetric linearization O(1,...,1). The intermediate blown-up spaces turn out to be the moduli spaces of weighted pointed stable curves for suitable ranges of weights. As an application, we provide a new unconditional proof of M. Simpson's Theorem about the log canonical models of the Mumford-Knudsen space. We also give a basis of the Picard group of the moduli spaces of weighted pointed stable curves.

Keywords

Cite

@article{arxiv.1002.2461,
  title  = {Moduli spaces of weighted pointed stable rational curves via GIT},
  author = {Young-Hoon Kiem and Han-Bom Moon},
  journal= {arXiv preprint arXiv:1002.2461},
  year   = {2010}
}

Comments

An error (Lemma 5.3 in v1) has been corrected.