2 citations · 4 across the 9 of their papers we have counts for
9 papers · 1 filter
Adjoint test modules along Cohen--Macaulay morphisms
Javier Carvajal-Rojas, Axel Stäbler
We provide a transformation rule for adjoint test modules along Cohen--Macaulay maps between Cohen--Macaulay varieties that have -rational geometric fibers. This is, in part, an…
Pulling back Cartier structures along regular maps
Javier Carvajal-Rojas, Axel Stäbler
We introduce a framework for pulling back Cartier modules and their associated invariants along regular -finite morphisms. To achieve this, we construct a relative Cartier isomo…
On pristine morphisms
Javier Carvajal-Rojas, Axel Stäbler
We investigate flat morphisms of schemes of positive characteristic whose relative Frobenius is an isomorphism, which we call pristine. We show that these give rise to a natural Gr…
Reductions of non-lc ideals and non -pure ideals assuming weak ordinarity
Axel Stäbler
Assume is a variety over , is a finitely generated -algebra and a model of (i.e. ).…
The associated graded module of the test module filtration
Axel Stäbler
We show that each direct summand of the associated graded module of the test module filtration admits a natural Cartier structure. If is an -jumping nu…
Intermediate extensions of perverse constructible -sheaves commute with smooth pullbacks
Axel Stäbler
We prove that intermediate extensions of perverse constructible -sheaves commute with smooth pullbacks for schemes admitting a closed embedding into a smooth scheme o…
Test module filtrations for unit -modules
Axel Stäbler
We extend the notion of test module filtration introduced by Blickle for Cartier modules. We then show that this naturally defines a filtration on unit -modules and prove that t…
On base change of the fundamental group scheme
Axel Stäbler
We provide for all prime numbers examples of smooth projective curves over a field of characteristic for which base change of the fundamental group scheme fails. This is in…
An explicit computation of a family of trivialising étale covers
Axel Stäbler
We explicitly compute étale covers of the smooth Fermat curves $Y_{p+1} = \Proj k[u,v,w]/(u^{p+1} + v^{p+1} - w^{p+1})$ which trivialise the vector bundles $\Syz(u^2, v^2, w^2)(3)$…