Thomas Rüd

Number Theory Representation theory Automorphic Forms

I am a mathematician working at the interface of representation theory and number theory. I am currently a postdoc at the Massachusetts Institute of Technology under the mentorship of Wei Zhang. Previously, I was a graduate student at the University of British Columbia under the supervision of Julia Gordon.

Orbital Integrals Buildings Langlands Program Local–Global Principle
Portrait of Thomas Rüd
Research

Research

My work explores the structure of p-adic groups and their buildings, with a particular emphasis on relative trace formulas, orbital integrals on p-adic symmetric spaces, and local–global principles in the Langlands framework. I am especially interested in refinements of the relative Langlands program and ideas inspired by Beyond Endoscopy.

Download Research Statement(PDF)

Current themes

  • Comparison of Orbital integrals
  • Transfer of automorphic representations for spherical pairs
  • Beyond Endoscopy and detection of functorial transfers
  • Local–global principles and relations to cohomology of tori
  • New interpolation tensor categories.

Ongoing projects

  • Explicit constructions of transfer for the Arithmetic Transfer Conjecture.
  • Orbital integrals on classical groups as point counts and explicit formulas.
  • Oligomorphic groups and constructions of tensor categories.
  • Computation of orbital integrals in symplectic groups and low-regular Shalika germs.
Awards

Awards & Fellowships

  • 2025
    SPOT Award
    Prize  Awarded by MIT math department in recognition for outstanding achievements.
  • 2025
    Lusztig Mentorship Award
    Prize  Awarded by MIT math department in recognition of my mentorship in the PRIMES USA Program.
  • 2024
    Charles and Molly Houseman Award
    Prize  Awarded by MIT math department in recognition for excellence in undergraduate teaching.
  • 2022–2024
    Postdoctoral Fellowship
    Fellowship   Funded by the Swiss National Science Foundation.
  • 2020
    Graduate Research Award
    Prize  Awarded by UBC math department in recognition for thesis and research work.
Publications & Preprints

Preprints

  • 2025
    Jacquet—Rallis transfer for ramified quadratic extensions
    Preprint  with W. Zhang, Preprint. In late stage of preparation, pdf already available on demand.
    Arithmetic Transfer Relative Langlands Program Unitary groups
  • 2025
    Orbital integrals for linear groups as local densities
    Preprint  with M.Middlezong and L.Qi, Preprint. Link
    Orbital Integrals Local Densities
  • 2025
    Oligomorphic groups: Measures on colored trees and cyclic orders
    Preprint  with T. Can, Preprint. In late stage of preparation, pdf already available on demand.
    Oligomorphic Groups Fraïssé classes Measures Tensor categories
  • 2025
    A comparison problem for abelian surfaces and descent for symplectic orbital integrals
    Preprint  Preprint, 82p. arXiv
    Orbital Integrals Abelian Varieties Elliptic curves
  • 2024
    A Projective Twist on the Hasse Norm Theorem
    Submitted  with A. Bu, Submitted, 25 p. arXiv
    Local–Global Principle Number Theory

Selected Publications

  • 2023
    Appendix of: Counting abelian varieties over finite fields via Frobenius densities by by J. Achter, S. Altug, L. Garcia, and J. Gordon.
    Published  Algebra and Number Theory, (2023)
    Galois Cohomology Algebraic Tori Local-Global Principle
  • 2021
    Explicit Tamagawa numbers for certain algebraic tori over number fields
    Published  Mathematics of Computation, 143 (2022)
    Galois Cohomology Algebraic Tori Local-Global Principle
  • 2019
    On uniform admissibility of unitary and smooth representations
    Published  with U. First. Archiv der Mathematik (2019)
    Representation Theory

A complete list of publications is available on my curriculum vitae and on arXiv.

Teaching & Mentoring

Teaching & Mentoring

I enjoy teaching algebra, number theory, and representation theory but I also learn sharing my excitment in all aspects of mathematics including calculus and geometry.

Upcoming Course

  • 18.704 Seminar in algebra @MIT
     (CIM course) — Seminar on fourier analysis on groups and hyperbolic surfaces.

Current course

  • 18.02 Multivariable calculus (2025) @MIT

Supervision

  • Eunsu Hur 2026 @MIT DRP
      Directed Reading program, topic TBA
  • Michael Middlezong and Lucas Qi 2025 @MIT PRIMES
      Year long research program as part of MIT PRIMES USA, we worked on explicit computations of orbital integrals.
  • Thanh Can 2025 @MIT PRIMES
      Year long research program as part of MIT PRIMES USA, we worked on classification of measures on Oligomorphic groups.
  • Luis Turino and Cedric Xiao 2024 @MIT DRP
      Directed Reading program, we read structure of elliptic curves over finite fields and applications to cryptography.
  • George Shaker 2023 @MIT DRP
      Directed Reading program, we read on Fourier analysis and the spectrum of the Laplacian for hyperbolic surfaces.
  • Alan Bu 2023 @MIT PRIMES
      Year long research program as part of MIT PRIMES USA, we worked on new versions of local-global norm principles.

For stu

Previous courses

  • 18.01 Single variable calculus (2025) @MIT
  • 18.01A/02A Accelerated course in single and multi variable calculus (2024) @MIT
  • 18.781 Theory of Numbers (2024) @MIT
  • Lead instructor for Petey Greene's prison education program. Framingham medium security prison (2023)
  • 18.01A/02A Accelerated course in single and multi variable calculus (2022) @MIT
  • MATH 104: Differential calculus (2021) @UBC
  • MATH 100 Vantage: Differential calculus (2021) @UBC
  • MATH 184: Differential calculu (2019) @UBC
  • MATH 104: Differential calculus (2018) @UBC

For students

If you are interested in a reading course or research project related to these topics, feel free to email me with a brief description of your background and mathematical interests.

Writing

Expository & Short Writing

I enjoy drawing on Tikz (as can be seen in the background images) and occasionally wrote notes as part of projects, of potential interest.

  • Compilation of Building drawings
    Feel free to reach out for the LaTeX code if you wish to modify them. PDF
  • Short slides outlining my research directions as of 2024
    PDF
  • Slides covering my thesis work
    Colloquium slides. PDF
  • Introduction to admissibility of representations of p-adic groups.
    Master Thesis. PDF
Talks

Recent & Upcoming Talks

  • 2025
    Explicit construction of arithmetic transfer in the ramified unitary setting
    Number Theory Seminar, University of Maryland, Park City. Seminar
  • 2025
    Relative Langlands program and Functoriality
    Conference: Celebrating 100 years of the mathematics building at UBC. Conference
  • 2023
    Buildings, orbital integrals, and Harmonic Analysis
    Workshop on Beyond Endoscopy, Fields Institute Workshop
CV

Curriculum Vitae

A CV containing details about my positions, publications, teaching, and service is available as a PDF.

Download CV(PDF)

Last updated: November 2025.

Misc.

Miscellaneous

Outside of mathematics, some of my time goes into movement, music, and things that still have a bit of structure and rhythm.

All Gymnastics Fencing Grading

Photos

Contact

Contact

Email
rud [at] mit.edu
Office
Office 2-171
Mailing Address
Massachusetts Institute of Technology
77 Massachusetts Avenue
Camberidge, MA, 02139
USA

Links

Office Hours

Please email to schedule an appointment. I am happy to meet with students to discuss coursework, reading projects, or research ideas.