works on

From the 1 of 10 linked papers with an AI index.

activity
20242026
collaborators

10 papers

math.AG2026

Invisible singularities in complex algebraic geometry

Maurício Corrêa, János Kollár, Stefan Schreieder +1

We construct morphisms between smooth complex projective varieties that have singular fibers, but look topologically smooth. We use this to give negative answers to the following f…

math.AG2026

Zeros of one-forms and the topology of algebraic maps

Stefan Schreieder, Botong Wang

The authors construct smooth complex projective varieties whose Albanese morphisms are homotopy fiber bundles but not submersions, and whose holomorphic one-forms always have zeros…

math.AG2026

Matroids and the integral Hodge conjecture for abelian varieties

Philip Engel, Olivier de Gaay Fortman, Stefan Schreieder

We prove that the cohomology class of any curve on a very general principally polarized abelian variety of dimension at least 4 is an even multiple of the minimal class. The same h…

math.AG2026

Combinatorics and Hodge theory of degenerations of abelian varieties: A survey of the Mumford construction

Philip Engel, Olivier de Gaay Fortman, Stefan Schreieder

We survey the Mumford construction of degenerating abelian varieties, with a focus on the analytic version of the construction, and its relation to toric geometry. Moreover, we stu…

math.AG2025

Cycle conjectures and birational invariants over finite fields

Samet Balkan, Stefan Schreieder

We study a natural birational invariant for varieties over finite fields and show that its vanishing on projective space is equivalent to the Tate conjecture, the Beilinson conject…

math.AG2025

On the rationality problem for low degree hypersurfaces

Jan Lange, Stefan Schreieder

We show that a very general hypersurface of degree d at least 4 and dimension at most over a field of characteristic different from 2 does not admit a decomposition…