activity
20032026
most citedHomological interpretation of extensions and biextensions of 1-motives

9 citations · 32 across the 21 of their papers we have counts for

collaborators

26 papers

math.NT2026

Algebraic independence of the exponential and Weierstrass -functions

Cristiana Bertolin

Let be a lattice in with algebraic invariants and complex multiplication, let be the elliptic curve associated with , and let be the Weierst…

math.AG2026

Dimension of the motivic Galois group of a 1-motive

Cristiana Bertolin

We compute the dimension of the motivic Galois group of a 1-motive M defined over the field of complex numbers, expressing it explicitly in terms of the rank of the multiplicative…

math.AG2026

1-motives and admissible variations of mixed Hodge structures

Cristiana Bertolin

Let S be a connected scheme smooth and of finite type over the field of complex numbers. To every 1-motive over S, André associated the enriched Hodge realization given by a torsio…

math.NT2025

A conjecture in Schanuel style for 1-motives

Cristiana Bertolin

Schanuel Conjecture contains all ``reasonable" statements that can be made on the values of the exponential function. In particular it implies the Lindemann-Weierstrass Theorem. In…

math.NT2025

Variations on Schanuel's Conjecture for elliptic and quasi-elliptic functions I: the split case

Cristiana Bertolin, Michel Waldschmidt

It is expected that Schanuel's Conjecture contains all ``reasonable" statements that can be made on the values of {\em the exponential function}. In particular it implies the Linde…

math.AG2023

The group law of Picard stacks via matrices

Cristiana Bertolin, Federica Galluzzi

Let S be a site. We show that the 2-stack of strictly commutative Picard stacks over S is algebraic, i.e. it is 2-equivalent to the 2-stack of 2-algebras for an adequate algebraic…

math.AG2022★ 1 cited

Mumford-Tate groups of 1-motives and Weil pairing

Cristiana Bertolin, Patrice Philippon

We show how the geometry of a 1-motive (that is existence of endomorphisms and relations between the points defining it) determines the dimension of its motivic Galois group ${…

math.NT2020

Semi-abelian analogues of Schanuel Conjecture and applications

Cristiana Bertolin, Patrice Philippon, Biswajyoti Saha +1

In this article we study Semi-abelian analogues of Schanuel conjecture. As showed by the first author, Schanuel Conjecture is equivalent to the Generalized Period Conjecture applie…

math.NT2019

Third kind elliptic integrals and 1-motives

Cristiana Bertolin

In our PH.D. thesis we have showed that the Generalized Grothendieck's Conjecture of Periods applied to 1-motives, whose underlying semi-abelian variety is a product of elliptic cu…

math.AG2019

A note on divisorial correspondences of extensions of abelian schemes by tori

Cristiana Bertolin, Federica Galluzzi

Let S be a locally noetherian scheme and consider two extensions G_1 and G_2 of abelian S-schemes by S-tori. In this note we prove that the fppf-sheaf Corr _S(G_1,G_2) of divisoria…

math.AG2017

Brauer groups of 1-motives

Cristiana Bertolin, Federica Galluzzi

Over a normal base scheme, we prove the generalized Theorem of the Cube for 1-motives and that a torsion class of the group H^2_ét(M,G_m)$ of a 1-motive M, whose pull-back via the…

math.AG2016★ 7 cited

Morphisms of 1-motives defined by line bundles

Cristiana Bertolin, Sylvain Brochard

Let be a normal base scheme. The aim of this paper is to study the line bundles on 1-motives defined over . We first compute a dévissage of the Picard group of a 1-motive $M…

math.AG2014★ 4 cited

Higher-dimensional study of extensions via torsors

Cristiana Bertolin, Ahmet Emin Tatar

Let S be a site. First we define the 3-category of torsors under a Picard S-2-stack and we compute its homotopy groups. Using calculus of fractions we define also a pure algebraic…

math.AG2012★ 7 cited

Extensions of Picard 2-Stacks and the cohomology groups Ext^i of length 3 complexes

Cristiana Bertolin, Ahmet Emin Tatar

The aim of this paper is to define and study the 3-category of extensions of Picard 2-stacks over a site S and to furnish a geometrical description of the cohomology groups Ext^i o…

math.AG2011

Biextensions of Picard stacks and their homological interpretation

Cristiana Bertolin

Let S be a site. We introduce the 2-category of biextensions of strictly commutative Picard S-stacks. We define the pull-back, the push-down, and the sum of such biextensions and w…

math.AG2010

Extensions and biextensions of locally constant group schemes, tori and abelian schemes

Cristiana Bertolin

Let S be a scheme. We compute explicitly the group of homomorphisms, the S-sheaf of homomorphisms, the group of extensions, and the S-sheaf of extensions involving locally constant…

math.AG2010

Extensions of Picard stacks and their homological interpretation

Cristiana Bertolin

Let S be a site. We introduce the notion of extensions of strictly commutative Picard S-stacks. We define the pull-back, the push-down, and the sum of such extensions and we comput…

math.AG2009★ 1 cited

Deligne's conjecture on extensions of 1-motives

Cristiana Bertolin

We introduce the notion of extension of 1-motives. Using the dictionary between strictly commutative Picard stacks and complexes of abelian sheaves concentrated in degrees -1 and 0…

math.KT2009

Biextensions of 1-motives in Voevodsky's category of motives

Cristiana Bertolin, Carlo Mazza

Let k be a perfect field. In this paper we prove that biextensions of 1-motives define multilinear morphisms between 1-motives in Voevodsky's triangulated category of effective geo…

math.AG2008★ 9 cited

Homological interpretation of extensions and biextensions of 1-motives

Cristiana Bertolin

Let k be a separably closed field. Let K_i=[A_i \to B_i] (for i=1,2,3) be three 1-motives defined over k. We define the geometrical notions of extension of K_1 by K_3 and of biexte…

math.AG2007

Some tensor products

Cristiana Bertolin

We define the tensor product of 1-motives with motives of weight 0 and we construct explicitely the 1-motive underlying the quotient M_1 \otimes M_2 / W_{-3}(M_1 \otimes M_2).

math.NT2007★ 1 cited

Multilinear morphisms between 1-motives

Cristiana Bertolin

Let S be an arbitrary scheme. We define biextensions of 1-motives by 1-motives which we see as the geometrical origin of morphisms from the tensor product of two 1-motives to a thi…

math.AG2005

Some motivic pairings

Cristiana Bertolin

In this note we prove the geometrical origin of pairings of abelian schemes. According to Deligne's philosophy of motives, this means that these pairings are motivic. We make also…

math.NT2005

Realizations of Biextensions

Cristiana Bertolin

Let k be a field of characteristic 0 and M(k) is the category of 1-motives over k. We prove that Biext^1(M_1,M_2;M_3)=Hom_{MR(k)}(T(M_1)\otimes T(M_2), T(M_3))