Chow Quotients of Grassmannians II
Abstract
Description
We consider Kapranov's Chow quotient compactification of the moduli space of ordered n-tuples of hyperplanes in P^{r-1} in linear general position. For r=2 this is canonically identified with the Grothendieck-Knudsen compactification of M_{0,n} which has among others the nice properties 1) Modular meaning: stable pointed rational curves 2) Canonical description of limits of one parameter degenerations 3) Natural Mori theoretic meaning: log canonical compactification. We prove (1-2) generalize naturally to all (r,n), but that (3), which we view as the deepest, fails except possibly in the cases (2,n),(3,6),(3,7),(3,8), where we conjecture it holds. The same generalization of (1) was given recently (and independently) by Hacking.
Proofs in section 3 are simplified, some technical details and typos are corrected. The proof of 1.5 is removed - a more general modular result will appear in the joint paper with Paul Hacking
Proofs in section 3 are simplified, some technical details and typos are corrected. The proof of 1.5 is removed - a more general modular result will appear in the joint paper with Paul Hacking