2 papers
math.AG2025
Del Pezzo surfaces of Picard number one admitting a torus action
Daniel Haettig, Beatrice Hafner, Juergen Hausen +1
We present efficient classification algorithms for log del Pezzo surfaces with torus action of Picard number one and given Gorenstein index. Explicit results are obtained up to Gor…
math.AG2024
The Picard index of a surface with torus action
Justus Springer
We consider normal rational projective surfaces with torus action and provide a formula for their Picard index, that means the index of the Picard group inside the divisor class gr…