3 papers
math.AG2026
On Ziegler pairs of line arrangements: from non-existence to abundance
Alexandru Dimca, Piotr Pokora
We study Ziegler pairs of line arrangements from both numerical and homological perspectives. We distinguish classical Ziegler pairs, for which the minimal degree of a Jacobian rel…
math.AG2026
A nine-line counterexample to a conjecture on the minimal degree of Jacobian relations
Alexandru Dimca, Piotr Pokora
We construct two arrangements of nine lines in the complex projective plane with isomorphic intersection lattices but with different minimal degrees of Jacobian relations. The comm…
math.AG2026
Plane curve singularities and Fitting ideals
Alexandru Dimca, Gabriel Sticlaru
In this note we investigate the Fitting ideals associated to the Tjurina ideal of a non quasi-homogeneous plane curve singularity. Special properties occur when the difference betw…