9 citations · 23 across the 14 of their papers we have counts for
14 papers
Distributions with locally free tangent sheaf
J. V. Pereira, J. P. dos Santos
In the paper Stability of Holomorphic Foliations with Split Tangent Sheaf one finds a study of the locus where the tangent sheaf of a {\it family} of foliations in $…
Fiber criteria for flatness and homomorphisms of flat affine group schemes
Phùng Hô Hai, Hop D. Nguyen, João Pedro dos Santos
A very useful result concerning flatness in Algebraic Geometry is EGA's ``fiber'' criterion. We propose similar fiber criteria to verify flatness of a module while avoiding ``finit…
On the monodromy of holomorphic differential systems
Indranil Biswas, Sorin Dumitrescu, Lynn Heller +2
First we survey and explain the strategy of some recent results that construct holomorphic -differential systems over some Riemann surfaces of genus…
Prolongation of regular singular connections on punctured affine line over a Henselian ring
Phùng Hô Hai, João Pedro dos Santos, Pham Thanh Tâm +1
We generalize Deligne's equivalence between the categories of regular-singular connections on the formal punctured disk and on the punctured affine line to the case where the base…
Algebraic theory of formal regular-singular connections with parameters
Phùng Hô Hai, João Pedro dos Santos, Pham Thanh Tâm
This paper is divided into two parts. The first is a review, through categorical lenses, of the classical theory of regular-singular differential systems over and $\mathbb…
Connections on trivial vector bundles over projective schemes
Indranil Biswas, Phùng Hô Hai, João Pedro dos Santos
Over a smooth and proper complex scheme, the differential Galois group of an integrable connection may be obtained as the closure of the transcendental monodromy representation. In…
Regular-singular connections on relative complex schemes
Phùng Hô Hai, João Pedro dos Santos
Deligne's celebrated "Riemann--Hilbert correspondence" relates representations of the fundamental group of a smooth complex algebraic variety and regular-singular integrable connec…
On the fundamental group schemes of certain quotient varieties
Indranil Biswas, Phùng Hô Hai, João Pedro dos Santos
In \cite{armstrong}, M. Armstrong proved a beautiful result describing fundamental groups of quotient spaces. In this paper we prove an analogue of Armstrong's theorem in the setti…
On the structure of affine flat group schemes over discrete valuation rings, II
Phùng Hô Hai, João Pedro dos Santos
In the 1st part of this work [DHdS18], we studied affine group schemes over a discrete valuation ring (DVR) by means of Neron blowups. We also showed how to apply these findings to…
The action of the étale fundamental group scheme on the connected component of the essentially finite one
Phùng Hô Hai, João Pedro P. dos Santos
We follow the pattern in a recent paper of Otabe [Ota15] to define an action of the étale fundamental group scheme on the local component of the essentially finite…
On the structure of affine flat group schemes over discrete valuation rings
Nguyen Dai Duong, Phung Ho Hai, João Pedro P. dos Santos
We study affine group schemes over a discrete valuation ring using two techniques: Neron blowups and Tannakian categories. We employ the theory developed to define and study di…
Abelianization of the F-divided fundamental group scheme
Indranil Biswas, João Pedro P. dos Santos
Let be a pointed smooth proper variety defined over an algebraically closed field. The Albanese morphism for produces a homomorphism from the abelianization o…
Vector bundles trivialized by proper morphisms and the fundamental group scheme, II
Indranil Biswas, Joao Pedro dos Santos
Let be a projective and smooth variety over an algebraically closed field . Let be a proper and surjective morphism of -varieties. Assuming that is…
Vector bundles trivialized by proper morphisms and the fundamental group scheme
Indranil Biswas, Joao Pedro P. dos Santos
Let X be a smooth projective variety defined over an algebraically closed field k. Nori constructed a category of vector bundles on X, called essentially finite vector bundles, whi…