activity
20122025
most citedAutomorphy and irreducibility of some l-adic representations

36 citations · 109 across the 20 of their papers we have counts for

collaborators

23 papers

math.NT2025

Compatibility of -isocrystals on adjoint Shimura varieties

Jake Huryn, Kiran S. Kedlaya, Christian Klevdal +1

In this article, we extend past results of the last two authors to include compatibility of canonical -adic local systems and canonical -isocrystals on adjoint Shimura var…

math.NT2025

Compatibility of canonical -adic local systems on Shimura varieties, II

Stefan Patrikis

Let be a Shimura datum. In previous work with Christian Klevdal, we showed that the canonical -valued local systems on Shimura varieties for form…

math.NT2023

Compatibility of canonical -adic local systems on Shimura varieties

Christian Klevdal, Stefan Patrikis

For a Shimura variety in the superrigid regime and neat level subgroup , we show that the canonical family of -adic representations associated to a number field…

math.NT2022

Trianguline lifts of global mod Galois representations

Najmuddin Fakhruddin, Chandrashekhar Khare, Stefan Patrikis

We show that under a suitable oddness condition, irreducible mod representations of the absolute Galois group of an arbitrary number field have characteristic zero lifts which…

math.AG2020

G-rigid local systems are integral

Christian Klevdal, Stefan Patrikis

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

math.NT2020

Lifting and automorphy of reducible mod p Galois representations over global fields

Najmuddin Fakhruddin, Chandrashekhar Khare, Stefan Patrikis

We extend the lifting methods of our previous paper to lift reducible odd representations of Galois groups of global fields valued…

math.NT2019★ 2 cited

Potential automorphy of -valued Galois representations

Stefan Patrikis, Shiang Tang

We prove a potentially automorphy theorem for suitable Galois representations and $Γ_{F^+} \to \mathrm{GSpin}_{2n+1}(\o…

math.NT2019

Lifting -irreducible but -reducible Galois representations

Najmuddin Fakhruddin, Chandrashekhar Khare, Stefan Patrikis

In recent work, the authors proved a general result on lifting -irreducible odd Galois representations , with $…

math.NT2019

Relative deformation theory, relative Selmer groups, and lifting irreducible Galois representations

Najmuddin Fakhruddin, Chandrashekhar Khare, Stefan Patrikis

We study irreducible odd mod Galois representations , for a totally real number field and a ge…

math.NT2018★ 5 cited

Lifting irreducible Galois representations

Najmuddin Fakhruddin, Chandrashekhar Khare, Stefan Patrikis

We study irreducible mod p representations, valued in general reductive groups, of the Galois group of a number field. When the number field is totally real, we show that odd repre…

math.NT2018★ 1 cited

Compatible systems of Galois representations associated to the exceptional group E6

George Boxer, Frank Calegari, Matthew Emerton +3

We construct, over any CM field, compatible systems of l-adic Galois representations that appear in the cohomology of algebraic varieties and have (for all l) algebraic monodromy g…

math.NT2017★ 6 cited

G-Valued Galois Deformation Rings when

Jeremy Booher, Stefan Patrikis

For a smooth group scheme over an extension of such that the generic fiber of is reductive, we study the generic fiber of the Galois deformation ring for a $…

math.NT2016

Residual irreducibility of compatible systems

Stefan Patrikis, Andrew Snowden, Andrew Wiles

We show that if is a compatible system of absolutely irreducible Galois representations of a number field then the residual representation is abs…

math.NT2016

Deformations of Galois representations and exceptional monodromy, II: raising the level

Stefan Patrikis

Building on lifting results of Ramakrishna, Khare and Ramakrishna proved a purely Galois-theoretic level-raising theorem for two-dimensional odd representations of the Galois group…

math.NT2016★ 2 cited

Generalized Kuga-Satake theory and good reduction properties of Galois representations

Stefan Patrikis

In previous work we described when a single geometric representation, valued in a linear algebraic group, of the Galois group of a number field lifts through a central torus quotie…

math.NT2015★ 29 cited

Deformations of Galois representations and exceptional monodromy

Stefan Patrikis

For any simple algebraic group of exceptional type, we construct geometric -adic Galois representations with algebraic monodromy group equal to , in particular produci…

math.NT2015★ 6 cited

Anabelian geometry and descent obstructions on moduli spaces

Stefan Patrikis, José Felipe Voloch, Yuri Zarhin

We study the section conjecture of anabelian geometry and the sufficiency of the finite descent obstruction to the Hasse principle for the moduli spaces of principally polarized ab…

math.NT2014★ 2 cited

Generalized Kuga-Satake theory and rigid local systems, I: the middle convolution

Stefan Patrikis

This note explains an approach to producing examples of 'generalized Kuga-Satake theory' based on establishing special cases of Simpson's conjecture that rigid local systems are mo…

math.NT2014★ 3 cited

Generalized Kuga-Satake theory and rigid local systems, II: rigid Hecke eigensheaves

Stefan Patrikis

This paper uses rigid Hecke eigensheaves, building on Yun's work on the construction of motives with exceptional Galois groups, to produce the first robust examples of `generalized…

math.NT2013★ 36 cited

Automorphy and irreducibility of some l-adic representations

Stefan Patrikis, Richard Taylor

In this paper we prove that a pure, regular, totally odd, polarizable weakly compatible system of -adic representations is potentially automorphic. The innovation is that we mak…

math.NT2013

On the sign of regular algebraic polarizable automorphic representations

Stefan Patrikis

We remove a parity condition from the construction of automorphic Galois representations carried out in the Paris Book Project. We subsequently generalize this construction to the…

math.AG2013

Mumford-Tate groups of polarizable Hodge structures

Stefan Patrikis

We classify the possible Mumford-Tate groups of polarizable rational Hodge structures. Along the way we deduce a polarized Hodge-theoretic analogue of a conjectural property of mot…

math.NT2012★ 17 cited

Variations on a theorem of Tate

Stefan Patrikis

Let be a number field. These notes explore Galois-theoretic, automorphic, and motivic analogues and refinements of Tate's basic result that continuous projective representation…