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Xiaoyu ZHANG

I am a Research Assistant in the group of Massimo Bertolini, ESAGA, faculty of mathematics, Universität Duisburg-Essen, Germany. I obtained my PhD in June 2019 in Université Paris 13, France, under the supervision of Jacques Tilouine.

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My research interests include p-adic automorphic forms, modularity lifting, theta correspondence, Iwasawa theory.

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E-mail: MyFirstName.MyLastName@uni-due.de,

Address: Fakultät Mathematik, Thea-Leymann-Straße 9, 45127 Essen (here)

Research

​(Pre)publications:

  1. Selmer groups of symmetric powers of ordinary modular Galois representations, American Journal of Mathematics, Vol.143, no.1 (2021), 10.1353/ajm.2021.0002.

  2. On the convergence of certain indefinite theta series, Acta Arithmetica 215 (2024), 309-325, DOI: 10.4064/aa230418-10-3.

  3. (with Heer Zhao) Honda-Tate theory for log abelian varieties over finite fields, https://arxiv.org/abs/2404.16639, submitted.

  4. Simultaneous supersingular reductions of Hecke orbits, https://arxiv.org/abs/2306.02290, submitted.

  5. Non-vanishing mod $p$ of theta lifts, https://arxiv.org/abs/2203.05359, submitted.

  6. Minimal modularity lifting theorems for definite special orthogonal groups, https://arxiv.org/abs/2411.04897, submitted.

  7. Hida theory for Shimura varieties of Hodge type, https://arxiv.org/abs/2104.11941.

  8. Special $L$-values and Selmer groups of Siegel modular forms of genus $2$, https://arxiv.org/abs/1811.02031.

Teaching

  1. Winter Semester 2024: Modular Forms-1 (joint with Prof. Bertolini, UDE)

  2. Summer Semester 2024: Seminar on Number Theory: Abelian Galois Representations (joint with Dr. Jie LIN, UDE)

  3. Summer Semester 2024: Modular Forms-1 (joint with Dr. Jie LIN, UDE)

  4. Winter Semester 2023: Seminar on Number Theory: Elliptic Curves (joint with Jie Lin, UDE)

  5. Winter Semester 2023: Modular Forms-1 (joint with Dr. Jie LIN, UDE)

  6. Summer Semester 2023: Seminar on Number theory: Euler systems (UDE)

  7. Summer Semester 2023: Modular Forms-2, Exercise Session (UDE)

  8. Winter Semester 2022: Seminar on Number theory: Iwasawa theory and zeta values (UDE)

  9. Winter Semester 2022: Modular Forms-1, Exercise Session (UDE)

  10. Summer Semester 2022: Seminar on Algebraic Geometry (UDE)

  11. Summer Semester 2022: Modular Forms-2, Exercise Session (UDE)

  12. Winter Semester 2021: Algebraic Geometry-3, Exercise Session (UDE)

  13. Winter Semester 2021: Modular Forms-1, Exercise Session (UDE)

  14. Summer Semester 2021: Algebraic Geometry-2, Exercise Session (UDE)

  15. Summer Semester 2021: Master Seminar 'Local fields' (UDE)

  16. Winter Semester 2020: Algebraic Geometry-1, Exercise Session (UDE)

  17. Winter Semester 2020: Master Seminar 'Elliptic Curves' (UDE)

  18. Summer Semester 2020: Modular Forms-2 (UDE)

  19. Summer Semester 2020: PhD Seminar 'Beilinson Conjecture' (UDE)

  20. Winter Semester 2019: Modular Forms-1, Exercise Session (UDE)

  21. Winter Semester 2019: Bachelor Seminar 'Representation of finite groups' (UDE)

  22. Summer Semester 2019: Algèbre Linéaire for 1st year undergraduate students of CS (UP13)

  23. Winter Semester 2018: Outils mathématiques for 1st year undergraduate students of mathematics (UP13)

  24. Winter Semester 2017: Algèbre Linéaire (UP13)

  25. Summer Semester 2017: Analyse (UP13)

Conferences/Talks/Visits

  1. Kiel, November 2024, talk 'Mod p theta liftings for unitary groups and Bloch-Kato conjecture'

  2. Amsterdam, May 2024, talk 'Modularity lifting theorems for SO(n) and applications to Bloch-Kato conjecture'

  3. EPFL, Nov 16 2023, talk 'Superspecial reduction of CM abelian varieties'

  4. ENTR Workshop, Bielefeld, August 2023, talk 'Theta liftings modulo p for unitary groups'

  5. Iwasawa 2023 in memorial of John Coates, Cambridge, July 2023

  6. Special values of L-functions, Paderborn, March 2023

  7. Motives and automorphic forms-in honor of Günter Harder's 85 birthday, Bonn, March 2023, talk 'Restriction problem of Hilbert theta series'

  8. ENTR workshop, Darmstadt, October 2023, talk 'On the convergence of indefinite theta series'

  9. Ellptic curves and modular forms in arithmetic geometry, Milan, September 2022

  10. Summer school on arithmetic geometry, Essen, September 2022

  11. Number theory and geometry in Zurich, Zurich, July 2022

  12. Community-building in the Langlands Program, August 2022, Bonn

  13. Rendez-Vous on special values and periods (online conference), May 2021, talk 'p-part Bloch-Kato conjecture for Siegel modular forms of genus 2'

  14. L-values and Iwasawa theory (online conference), November 2020, talk 'p-primitivity of theta lifts and L-values'

  15. LAGA, Université Paris 13, June 2020, talk 'Non-annulation mod p de transfert de thêta'

  16. DMATH, Luxembourg, Feburary 2020, talk 'Hida theory for GSpin Shimura varieties'

  17. IRMA, Strasbourg, January 2020, talk 'famille p-adique des formes modulaires'

  18. Academia Sinica, Taipei, August 2019, talk 'Selmer groups, congruence ideals for Siegel modular forms'

  19. USTC, Heifei, May 2019, talk 'Bloch-Kato conjectures for modular forms on GSp(4)'

  20. Regensbourg, January 2019, talk 'Automorphic type Bloch-Kato conjectures for Siegel modular forms of genus 2'

  21. Mathjeunes, Paris, December 2018, talk 'Control theorem of certain Selmer groups along the cyclotomic tower'

  22. ESAGA, Essen, November 2018, talk 'Special L-values and Selmer groups of Siegel modular forms of genus 2'

  23. MCM, Beijing, November 2017, talk 'Selmer groups and congruence ideals of symmetric powers of modular forms'

  24. Iwasawa 2017, Tokyo, July 2017

  25. Journées Arithmétiques, Caen, July 2017

  26. p-adic aspects of automorphic forms, Tehren, April-May 2017

  27. 21st London-Paris Number Theory Seminar, November 2016

Conferences organised

  1. ENTR Workshop 24, Early Number Theory Researchers Workshop (link)

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