Searcharxiv⌕ Search

arXiv · 0708.1228

On the collisions of singular points of complex algebraic plane curves

Abstract

We study the "generic" degenerations of curves with two singular points when the points merge. First, the notion of generic degeneration is defined precisely. Then a method to classify the possible results of generic degenerations is proposed in the case of linear singularity types. We discuss possible bounds on the singularity invariants of the resulting type in terms of the initial types. In particular the strict upper bound on the resulting multiplicity is proved and a sufficient condition for $δ=const$ collision is given.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Dmitry Kerner. 2009-04-21. On the collisions of singular points of complex algebraic plane curves. https://arxiv.org/abs/0708.1228

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Canonical coordinates for moduli spaces of rank two irregular connections on curves

In this paper, we study a geometric counterpart of the cyclic vector which allow us to put a rank 2 meromorphic connection on a curve into a ``companion'' normal form. This allow us to naturally identify an open set of the moduli space of $\mathrm{GL}_2$-connections (with fixed generic spectral data, i.e. unramified, non resonant) with some Hilbert scheme of points on the twisted cotangent bundle of the curve. We prove that this map is symplectic, therefore providing Darboux (or canonical) coordinates on the moduli space, i.e. separation of variables. On the other hand, for $\mathrm{SL}_2$-connections, we give an explicit formula for the symplectic structure for a birational model given by Matsumoto. We finally detail the case of an elliptic curve with a divisor of degree $2$.

math.AG↗

Group Actions from Algebraic Flops

This paper constructs derived autoequivalences associated to an algebraic flopping contraction X --> X_con, where X is quasi-projective with only mild singularities. These functors are constructed naturally using bimodule cones, and we prove these cones are locally two-sided tilting complexes by using the local-global properties and a key commutative diagram. The main result is that these autoequivalences combine to give an action of the fundamental group of an associated infinite hyperplane arrangement on the derived category of X. This generalises and simplifies \cite{DW3}, by finally removing reliance on subgroups, and it also lifts many other results from the complete local setting.

math.AG↗

Unramified Gromov-Witten and Gopakumar-Vafa invariants

Kim, Kresch, and Oh defined unramified Gromov-Witten invariants. For threefolds, Pandharipande conjectured that these invariants are equal to the Gopakumar-Vafa (BPS) invariants for Fano and primitive Calabi-Yau curve classes. We prove the conjecture using a wall-crossing method developed here. As a result, we obtain an algebro-geometric construction of Gopakumar-Vafa invariants in these cases.

math.AG↗