Semigroups, d-invariants and deformations of cuspidal singular points of plane curves
arXiv:1305.2868
Abstract
We apply Heegaard Floer homology to study deformations of singularities of plane algebraic curves. Our main result provides an obstruction to the existence of a deformation between two singularities. Generalizations include the case of multiple singularities. The obstruction is formulated in terms of a semicontinuity property for semigroups associated to the singularities.
v2. 20 pages. Minor revision. Added comparison of the semigroup semicontinuity with a criterion obtained from the upsilon function of Ozsvath, Szabo and Stipsicz