Let X := A n R be the n-dimensional affine space over a discrete valuation ring R with fraction field K. We prove that any pointed torsor Y over A n K under the action of an affine finite-type group scheme can be extended ...

Let R be a discrete valuation ring with fraction field K. Let X be a proper and faithfully flat R-scheme, endowed with a section x∈X(R), with connected and reduced generic fibre Xη. Let f:Y→Xη be a finite Nori-reduced ...

LetRn be the ring of Laurent polynomials in n variables over a field k of characteristic zero and letKn be its fraction field. Given a linear algebraic κ-groupG,we showthat aKn-torsor under G which is unramified with respect ...

Given a relative faithfully at pointed scheme over the spectrum of a discrete valuation ring X !S, this paper is motivated by the study of the natural morphism from the fundamental group scheme of the generic ber X ...

Let X be any scheme defined over a Dedekind scheme S with a given section x ∈ X (S). We prove the existence of a pro-finite S-group scheme א (X,x) and a universal א (X,x)-torsor dominating all the pro-finite pointed torsors ...

We give a detailed description of the torsors that correspond to multiloop algebras. These algebras are twisted forms of simple Lie algebras extended over Laurent polynomial rings. They play a crucial role in the construction ...

As informações da avaliação de mecanismos de abertura de sulco de semeadoras de plantio direto auxiliam as empresas no dimensionamento de ferramentas rompedoras do solo, que buscam menor requerimento energético. Este ...

El principal objetivo es analizar la extensión de un G-torsor dado sobre la fibra genérica de X, donde X=AnRes el espacio afín n-dimensional sobre un anillo de valuación discreta R. Para ello primero se estudiará ...