arXiv subjects

Jakob Oesinghaus

Publications and source records attributed to Jakob Oesinghaus.

3 recordsLinked to original sources

arXiv2018

Quasi-symmetric functions and the Chow ring of the stack of expanded pairs

We show that the Hopf algebra of quasi-symmetric functions arises naturally as the integral Chow ring of the algebraic stack of expanded pairs originally described by J. Li, using a more combinatorial description in terms of configurations of line bundles. In particular, we exhibit a gluing map which gives rise to the comultiplication. We then apply the result to calculate the Chow rings of certain stacks of semistable curves.

math.AG↗

arXiv2018

Geometric Brauer residue via root stacks

We reinterpret the residue map for the Brauer group of a smooth variety using a root stack construction and Weil restriction for algebraic stacks, and apply the result to find a geometric representative of for the residue of a Brauer class associated to a conic bundle, or more generally a Brauer-Severi bundle.

math.AG↗

arXiv2018

Conic bundles and iterated root stacks

We generalize a classical result by V. G. Sarkisov about standard models for conic bundles to the case of a not necessarily algebraically closed perfect field, using iterated root stacks, destackification, and resolution of singularities.

math.AG↗