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Related papers: Rigid non-cohomologically rigid local systems

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We prove that the monodromy of an irreducible cohomologically complex rigid local system with finite determinant and quasi-unipotent local monodromies at infinity on a smooth quasiprojective complex variety $X$ is integral. This answers…

Algebraic Geometry · Mathematics 2018-01-30 Hélène Esnault , Michael Groechenig

We give a construction which produces irreducible complex rigid local systems on $\Bbb{P}_{\Bbb{C}}^1-\{p_1,\dots,p_s\}$ via quantum Schubert calculus and strange duality. These local systems are unitary and arise from a study of vertices…

Algebraic Geometry · Mathematics 2021-12-10 Prakash Belkale

We first develop some basic facts about certain sorts of rigid local systems on the affine line in characteristic $p>0$. We then apply them to exhibit a number of rigid local systems of rank $23$ on the affine line in characteristic $p=3$…

Number Theory · Mathematics 2018-10-18 Nicholas M. Katz , Antonio Rojas-León , Pham Huu Tiep

We give a classification of the orthogonally rigid local systems of rank 7 whose monodromy is dense in the exceptional algebraic group G2.

Algebraic Geometry · Mathematics 2012-09-26 Michael Dettweiler , Stefan Reiter

Let $G$ be a reductive group, and let $X$ be a smooth quasi-projective complex variety. We prove that any $G$-irreducible, $G$-cohomologically rigid local system on $X$ with finite order abelianization and quasi-unipotent local monodromies…

Algebraic Geometry · Mathematics 2020-09-22 Christian Klevdal , Stefan Patrikis

In this article, we construct integrally closed modules of rank two over a two-dimensional regular local ring. The modules are explicitly constructed from a given complete monomial ideal with respect to a regular system of parameters. Then…

Commutative Algebra · Mathematics 2018-09-24 Futoshi Hayasaka

We study the general properties of certain rank four rigid local systems considered by Goursat. We analyze when they are irreducible, give an explicit integral description as well as the invariant Hermitian form when it exists. By a…

Number Theory · Mathematics 2018-03-30 Danylo Radchenko , Fernando Rodriguez Villegas

We first develop some basic facts about hypergeometric sheaves on the multiplicative group ${\mathbb G}_m$ in characteristic $p >0$. Certain of their Kummer pullbacks extend to irreducible local systems on the affine line in characteristic…

Number Theory · Mathematics 2018-11-15 Nicholas M. Katz , Antonio Rojas-León , Pham Huu Tiep

The absolute sets of local systems on a smooth complex algebraic variety are the subject of a conjecture of N. Budur and B. Wang based on an analogy with special subvarieties of Shimura varieties. An absolute set should be the…

Algebraic Geometry · Mathematics 2022-02-18 Nero Budur , Leonardo A. Lerer , Haopeng Wang

In this paper, we construct indecomposable integrally closed modules of arbitrary rank over a two-dimensional regular local ring. The modules are quite explicitly constructed from a given complete monomial ideal. We also give structural and…

Commutative Algebra · Mathematics 2021-12-07 Futoshi Hayasaka

We consider all irreducible rank-4 hypergeometric local systems defined over $\mathbb{Q}$ that support a rational one-dimensional variation of Hodge structures of weight 3 and Hodge vector $(1,1,1,1)$. Up to a natural equivalence there are…

Algebraic Geometry · Mathematics 2024-01-25 Giulia Gugiatti , Fernando Rodriguez Villegas

We show that complex local systems with quasi-unipotent monodromy at infinity over a normal complex variety are Zariski dense in their moduli. v2: we waited for feedback and added a consequence of Alexandr Petrov's theorem. 3: we tightened…

Algebraic Geometry · Mathematics 2022-01-20 Hélène Esnault , Moritz Kerz

We exhibit a rigid local system of rank six on the affine line in characteristic $p=5$ whose arithmetic and geometric monodromy groups are the finite group $2.J_2$ ($J_2$ the Hall-Janko sporadic group) in one of its two (Galois-conjugate)…

Number Theory · Mathematics 2018-09-18 Nicholas M. Katz , Antonio Rojas-León

We study several rigidity properties of $p$-adic local systems on a smooth rigid analytic space $X$ over a $p$-adic field. We prove that the monodromy of the log isocrystal attached to a $p$-adic local system is ''rigid'' along irreducible…

Algebraic Geometry · Mathematics 2025-09-25 Hansheng Diao , Zijian Yao

Let $X/\mathbb{F}_{q}$ be a smooth geometrically connected variety. Inspired by work of Corlette-Simpson over $\mathbb{C}$, we formulate a conjecture that absolutely irreducible rank 2 local systems with infinite monodromy on $X$ come from…

Algebraic Geometry · Mathematics 2021-06-25 Raju Krishnamoorthy , Ambrus Pál

We introduce the general notions of an overconvergent site and a constructible crystal on an overconvergent site. We show that if $V$ is a geometric materialization of a locally noetherian formal scheme $X$ over an analytic space $O$…

Algebraic Geometry · Mathematics 2022-09-19 Bernard Le Stum

If in a given rank $r$, there is an irreducible complex local system with torsion determinant and quasi-unipotent monodromies at infinity on a smooth quasi-projective variety, then for every prime number $\ell$, there is an absolutely…

Algebraic Geometry · Mathematics 2023-02-22 Johan de Jong , Hélène Esnault

In earlier work of the author rigid irregular connections with differential Galois group $G_2$ and whose slopes have numerator $1$ were classified and new rigid connections were constructed. The same construction can be carried out for…

Algebraic Geometry · Mathematics 2024-02-06 Konstantin Jakob

This is a quick survey on the characteristic varieties associated to rank one local systems on a smooth, irreducible, quasi-projective complex variety $M$. A key new result is Proposition 1.8, giving additional information on the…

Algebraic Geometry · Mathematics 2007-05-23 Alexandru Dimca

A rank one local system $\LL$ on a smooth complex algebraic variety $M$ is 1-admissible if the dimension of the first cohomology group $H^1(M,\LL)$ can be computed from the cohomology algebra $H^*(M,\C)$ in degrees $\leq 2$. Under the…

Algebraic Geometry · Mathematics 2010-02-05 A. Dimca
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