Christian Johansson

I am a senior lecturer (universitetslektor) at the Department of Mathematical Sciences at Chalmers University of Technology and the University of Gothenburg.

Together with Anders Södergren, I organize at the Seminar in Algebraic Geometry and Number Theory at Chalmers/GU. The website can be found here.

My research interests are in algebraic number theory, primarily in the classical and p-adic Langlands program.

Curriculum vitae

Papers (comments and corrections are always welcome!)

"A note on the cohomology of moduli spaces of local shtukas". With David Hansen. Arxiv preprint. Submitted.

"Moduli stacks of Galois representations and the local Langlands correspondence for GL(2,Qp)". With James Newton and Carl Wang-Erickson. Arxiv preprint. Submitted.

"Endoscopy on SL(2)-eigenvarieties". With Judith Ludwig. Arxiv preprint. To appear in J. Reine Angew. Math.

"Politiska karteller och Sverigedemokraternas framgång". With Anders Kärnä and Jaakko Meriläinen. In "Folkviljans förverkligare", Gothenburg University Press, pp 117-133 (2022)


"Vox Populi, Vox Dei? Tacit collusion in politics". With Anders Kärnä and Jaakko Meriläinen. Journal website, Preprint. Economics & Politics, vol. 35(3), pp 752-772 (2023)

"Perfectoid Shimura varieties and the Calegari-Emerton conjectures". With David Hansen. Journal website, Arxiv preprint. Journal of the LMS, vol 108(5) pp 1954-2000 (2023)

"Vanishing theorems for Shimura varieties at unipotent level".  With Ana Caraiani and Daniel Gulotta. Journal website, Arxiv preprint. Journal of the EMS, vol. 25(3), pp 869-911 (2023)

"A quotient of the Lubin-Tate tower II". With Judith Ludwig, and with an appendix by David Hansen. Journal website, Arxiv preprint. Mathematische Annalen, vol. 380, pp 43-89 (2021)

"Shimura varieties at level Γ₁(p^∞) and Galois representations". With Ana Caraiani , Daniel Gulotta , Chi-Yun Hsu , Lucia Mocz , Emanuel Reinecke, Sheng-Chi Shih. Journal website, Arxiv preprint. Compositio Math., vol. 156(6), pp 1152-1230 (2020).

"On subquotients of the étale cohomology of Shimura varieties". With Jack Thorne. Arxiv preprint. In Shimura varieties, LMS Lecture Note Series 457, pp 306-334 (2020).

"Local Langlands correspondence in rigid families". With James Newton and Claus Sorensen. Journal website, Arxiv preprint. Pacific Journal of Mathematics, vol. 304(1), pp 65-102 (2020).

"Parallel weight 2 points on Hilbert modular eigenvarieties and the parity conjecture". With James Newton. Journal website, Arxiv preprint. Forum of Mathematics Sigma, vol. 7, e27, 36 pp (2019).

"Irreducible components of extended eigenvarieties and interpolating Langlands functoriality". With James Newton. Journal website, Arxiv preprint. Mathematical Research Letters, vol. 26(1), pp. 159-201 (2019).

"Extended eigenvarieties for overconvergent cohomology". With James Newton. Journal website, Arxiv preprint. Algebra and Number Theory, vol. 13(1), pp 93-158 (2019).

"Overconvergent modular forms and perfectoid Shimura curves". With Przemyslaw Chojecki and David Hansen. Journal website, Arxiv preprint. Documenta Mathematica, vol. 22, pp 191-262 (2017).

"On the Sato-Tate conjecture for non-generic abelian surfaces". With an appendix by Francesc Fité. Journal website, Arxiv preprint. Transactions of the A.M.S., vol. 369(9), pp 6303-6325 (2017).

"A trace formula approach to control theorems for overconvergent automorphic forms". Journal website, Arxiv preprint. Manuscripta Mathematica, vol. 151(1), pp 19-48 (2016).

"A canonical dimension estimate for non-split semisimple p-adic Lie groups". With Konstantin Ardakov. Journal website, Arxiv preprint. Representation Theory, vol. 20, pp 128-138 (2016).

"A remark on a conjecture of Buzzard-Gee and the cohomology of Shimura varieties". Journal website, Arxiv preprint. Mathematical Research Letters, vol. 20(2), pp 279-288 (2013).

"Classicality for small slope overconvergent automorphic forms on some compact PEL Shimura varieties of type C". Journal website , Arxiv preprint. Mathematische Annalen, vol. 357(1), pp 51-88 (2013).

Teaching

In autumn 2022 I taught TMV200/211 Diskret matematik at Chalmers. The course website is here.

In autumn 2021 I taught TMV200 Diskret matematik at Chalmers. The course website is here.

In autumn 2020 I taught TMV200 Diskret matematik at Chalmers. The course website is here.

In autumn 2019 I taught TMV200 Diskret matematik at Chalmers. The course website is here.


In autumn 2018 I taught LMA400 Matematisk Analys at Chalmers. The course website is here.

In Michaelmas 2017 I taught Part III Algebraic Number Theory at Cambridge. The course website is here.

In Michaelmas 2016 I taught Part III Local Fields at Cambridge. The course website is here.