Justus Springer

Publications

• Del Pezzo surfaces of Picard number one admitting a torus action. With Daniel Hättig, Beatrice Hafner and Jürgen Hausen. Annali di Matematica Pura ed Applicata (2025)
• Classifying log del Pezzo surfaces with torus action. With Daniel Hättig and Jürgen Hausen. Revista Matemática Complutense (2025).
• The Picard index of a surface with torus action. Collectanea Mathematica (2024).

Preprints

• Generalizations of Scott's inequality and Pick's formula to rational polygons. With Martin Bohnert.
• Classifying rational polygons with small denominator and few interior lattice points. With Martin Bohnert.

Software

My software projects can be found on my Github page. These include:

• CStarSurfaces.jl: A Julia package for computations with rational C*-surfaces.
• RationalPolygons.jl: A Julia package for computations with rational polygons.

Datasets

• ldp-database: A searchable web interface for log del pezzo surfaces admitting a non-trivial torus action.
• Several datasets of rational polygons are available on zenodo, for instance classifications of half-integral polygons up to 12 interior points and rational polygons with one interior point up to denominator four.

Contact information