Results 21 to 30 of about 296 (61)

A note on integrating group scheme actions

, 2015
We prove a non-integrability result concerning iterative derivations on projective line, where the iterative rule is given by a non-algebraic formal ...
Hoffmann, Daniel, Kowalski, Piotr
core   +1 more source

Finite flat models of constant group schemes of rank two

, 2009
We calculate the number of the isomorphism class of the finite flat models over the ring of integers of an absolutely ramified $p$-adic field of constant group schemes of rank two over finite fields, by counting the rational points of a moduli space of ...
Imai, Naoki
core   +2 more sources

A McKay Correspondence in Positive Characteristic

Forum of Mathematics, Sigma
We establish a McKay correspondence for finite and linearly reductive subgroup schemes of ${\mathbf {SL}}_2$ in positive characteristic.
Christian Liedtke
doaj   +1 more source

Existentially closed fields with G-derivations [PDF]

, 2015
We prove that the theories of fields with Hasse-Schmidt derivations corresponding to actions of formal groups admit model companions. We also give geometric axiomatizations of these model companions.Comment: In version 2: new proof of (the current ...
Hoffmann, Daniel, Kowalski, Piotr
core   +1 more source

Extention of Finite Solvable Torsors over a Curve

, 2010
Let $R$ be a discrete valuation ring with fraction field $K$ and with algebraically closed residue field of positive characteristic $p$. Let $X$ be a smooth fibered surface over $R$ with geometrically connected fibers endowed with a section $x\in X(R ...
F. Oort, J. Lipman, M. Antei, M. Antei, M. Antei, M. Demazure, M. Saïdi, M. Saïdi, M.A. Garuti, M.V. Nori, Marco Antei, S. Anantharaman, S. Maugeais, W.C. Waterhouse   +13 more
core   +1 more source

The de Rham cohomology of the Suzuki curves

, 2018
For a natural number $m$, let $\mathcal{S}_m/\mathbb{F}_2$ be the $m$th Suzuki curve. We study the mod $2$ Dieudonn\'{e} module of $\mathcal{S}_m$, which gives the equivalent information as the Ekedahl-Oort type or the structure of the $2$-torsion group ...
Malmskog, Beth, Pries, Rachel, Weir, Colin   +2 more
core   +1 more source

Effective model of a finite group action [PDF]

, 2006
Let $R$ be a discrete valuation ring with fraction field $K$. Let $X$ be a flat $R$-scheme of finite type and $G$ a finite flat group scheme acting on $X$ so that $G\_K$ is faithful on the generic fibre $X\_K$.
Romagny, Matthieu
core   +3 more sources

Monodromy group for a strongly semistable principal bundle over a curve, II

, 2006
Let $X$ be a geometrically irreducible smooth projective curve defined over a field $k$. Assume that $X$ has a $k$-rational point; fix a $k$-rational point $x\in X$.
Biswas, Indranil, Parameswaran, A. J.
core   +2 more sources

Gersten Conjecture For Equivariant K-theory And Applications

, 2009
For a reductive group scheme over a regular semi-local ring, we prove an equivarinat version of the Gersten conjecture. We draw some interesting consequences for the representation rings of such reductive group schemes. We also prove the rigidity for the
Krishna, Amalendu
core   +1 more source

On existence of canonical $G$-bases

, 2017
We describe a general method for expanding a truncated G-iterative Hasse-Schmidt derivation, where G is an algebraic group.
Hoffmann, Daniel M.
core   +1 more source