Elementary modifications and line configurations in P 2.

Autor: Henry K. Schenck
Zdroj: Commentarii Mathematici Helvetici; Jul2003, Vol. 78 Issue 3, p447-462, 16p
Abstrakt: Associated to a projective arrangement of hyperplanes ${\mathcal A}$ ? P n is the module D$({\mathcal A})$, which consists of derivations tangent to ${\mathcal A}$. We study D$({\mathcal A})$ when ${\mathcal A}$ is a configuration of lines in P 2. In this setting, we relate the deletion/restriction construction used in the study of hyperplane arrangements to elementary modifications of bundles. This allows us to obtain bounds on the Castelnuovo-Mumford regularity of D$({\mathcal A})$. We also give simple combinatorial conditions for the associated bundle to be stable, and describe its jump lines. These regularity bounds and stability considerations impose constraints on Terao?s conjecture. [ABSTRACT FROM AUTHOR]
Databáze: Supplemental Index