Concept
Crystalline cohomology
Related publications (32)
Unramified F-divided objects and the etale fundamental pro-groupoid in positive characteristic
Let X /S be a flat algebraic stack of finite presentation. We define a new & eacute;tale fundamental pro-groupoid pi(1)(X /S), generalizing Grothendieck's enlarged & eacute;tale fundamental group from SGA 3 to the relative situation. When S is of equal pos ...
GEOMETRY & TOPOLOGY PUBLICATIONS2022On p-adic Versions of the Manin-Mumford Conjecture
We establish p-adic versions of the Manin-Mumford conjecture, which states that an irreducible subvariety of an abelian variety with dense torsion has to be the translate of a subgroup by a torsion point. We do so in the context of certain rigid analytic s ...
OXFORD UNIV PRESS2021Realizing doubles: a conjugation zoo
Conjugation spaces are topological spaces equipped with an involution such that their fixed points have the same mod 2 cohomology (as a graded vector space, a ring and even an unstable algebra) but with all degrees divided by two, generalizing the classica ...
CAMBRIDGE UNIV PRESS2021Orders That Are Etale-Locally Isomorphic
Let R be a semilocal Dedekind domain with fraction field F. It is shown that two hereditary R-orders in central simple F-algebras that become isomorphic after tensoring with F and with some faithfully flat etale R-algebra are isomorphic. On the other hand, ...
AMER MATHEMATICAL SOC2020Orders that are étale-locally isomorphic
Eva Bayer Fluckiger, Mathieu Huruguen
Let R be a semilocal Dedekind domain with fraction field F. It is shown that two hereditary R-orders in central simple F-algebras that become isomorphic after tensoring with F and with some faithfully flat étale R-algebra are isomorphic. On the other hand, ...
2019Characteristic classes as complete obstructions
In the first part of this paper, we propose a uniform interpretation of characteristic classes as obstructions to the reduction of the structure group and to the existence of an equivariant extension of a certain homomorphism defined a priori only on a sin ...
SPRINGER HEIDELBERG2019Geometric stabilisation via $p$-adic integration
Dimitri Stelio Wyss, Michael Gröchenig
In this article we give a new proof of Ngô's Geometric Stabilisation Theorem, which implies the Fundamental Lemma. This is a statement which relates the cohomology of Hitchin fibres for a quasi-split reductive group scheme G to the cohomology of Hitchin fi ...
2018Hochschild homology and cohomology of down–up algebras
We present a detailed computation of the cyclic and the Hochschild homology and cohomology of generic and 3-Calabi–Yau homogeneous down–up algebras. This family was defined by Benkart and Roby in [3] in their study of differential posets. Our calculations ...
2018