Marco Antei

activity

20152018

collaborators

6 papers

math.AG2018

Models of torsors over affine spaces

Marco Antei, Jorge A. Esquivel A

Let $X := A_{R}^{n}$ be the $n$ -dimensional affine space over a discrete valuation ring $R$ with fraction field $K$ . We prove that any pointed torsor $Y$ over $\mathbb{A}^{n…

math.AG2017

Nori fundamental gerbe of essentially finite covers and Galois closure of towers of torsors

M. Antei, I. Biswas, M. Emsalem +2

We prove the existence of a Galois closure for towers of torsors under finite group schemes over a proper, geometrically connected and geometrically reduced algebraic stack $X$ ove…

math.AG2016

Towers of torsors over a field

Marco Antei, Indranil Biswas, Michel Emsalem

Let $X$ be a projective, connected and smooth scheme defined over an algebraically closed field $k$ . In this paper we prove that a tower of finite torsors (i.e., under the action o…

math.AG2016

Models of torsors and the fundamental group scheme

Marco Antei, Michel Emsalem

Given a relative faithfully flat pointed scheme over the spectrum of a discrete valuation ring $X \to S$ this paper is motivated by the study of the natural morphism from the funda…

math.AG2016

The pseudo-fundamental group-scheme

Marco Antei, Arijit Dey

Let $X$ be any scheme defined over a Dedekind scheme $S$ with a given section $x \in X (S)$ . We prove the existence of a pro-finite $S$ -group scheme $ℵ (X, x)$ and a universal $\a…

math.AG2015

On the bumpy fundamental group scheme

Marco Antei

In this short paper we first recall the definition and the construction of the fundamental group scheme of a scheme $X$ in the known cases: when it is defined over a field and when…