PeopleofSuperintelligence

Researcher

Michael Rothgang

Michael Rothgang is a mathematician whose work formalises mathematics with Lean and Mathlib. He coauthored a 2018 paper on Homotopy Hubbard Trees and completed a 2024 PhD on equivariant transversality at Humboldt-Universität zu Berlin. In a 2025 machine-learning-for-theorem-proving discussion, he described how scripts handle much of Mathlib’s upgrade work and coauthored Growing Mathlib, a paper about maintaining the library as it grows. He also coauthored a Lean formalisation of Carleson’s theorem in 2026. As of October 2026, he is a postdoctoral researcher in formalised mathematics at Bonn and a Mathlib maintainer.

Timeline

  1. 2018

    Homotopy Hubbard trees

    In 2018, he coauthors a paper that introduces Homotopy Hubbard Trees for exponential maps and uses them to classify post-singularly finite maps.

  2. Since 2023

    Formalising mathematics with Lean

    Since 2023, he formalises mathematics with Lean and works in the Mathlib community.

  3. By 2024

    A PhD in symplectic geometry

    Before coming to Berlin, he earns an undergraduate degree at Jacobs University Bremen and a master’s degree through the Berlin Mathematical School. At Humboldt-Universität zu Berlin, he completes a 2024 PhD with Chris Wendl on equivariant transversality for closed holomorphic curves.

  4. October 2024

    Postdoc with Floris van Doorn

    In October 2024, he is due to join Floris van Doorn’s research group as a postdoc, focusing on formalisation of analysis and symplectic geometry.

  5. May 2025

    Mathlib upgrades and machine learning

    At a May 2025 discussion on machine learning for theorem proving, he says simple scripts can handle 80% of Mathlib version-upgrade work through deprecations and import updates.

  6. 2025

    Growing Mathlib

    In 2025, he coauthors Growing Mathlib, a paper about maintaining the expanding Lean mathematical library through deprecations, linters, faster compilation and review tools.

  7. September 2026

    Carleson’s theorem in Lean

    In September 2026, he coauthors a paper presenting a formalisation of Carleson’s theorem in the proof assistant Lean.

  8. As of October 2026

    Bonn postdoc and Mathlib maintainer

    As of October 2026, he is a postdoctoral researcher in formalisation of mathematics at the University of Bonn and a Mathlib maintainer.

Career

  1. NowUniversity of BonnPostdoctoral researcher in formalised mathematics

Education

  1. 2024Humboldt-Universität zu BerlinPhD
  2. Jacobs University BremenUndergraduate degree
  3. Berlin Mathematical SchoolMaster's degree

From the biography.

  1. The Massachusetts Institute of Technology trained or employed 44 of the 187 AI major-prize winners, more than any other universityIncludes University of Bonn. The Massachusetts Institute of Technology trained or employed 44 of the 187 AI major-prize winners, more than any other university. We compare doctorate and 5+ year employment links, career timing and current workplaces for 187 major-prize and 1,111 best-paper winners.
  2. More people shaping AI studied at Massachusetts Institute of Technology than at any other institutionIncludes University of Bonn. We estimate where the people shaping AI studied and where their careers led. Massachusetts Institute of Technology leads with 467 former students, including 291 recorded doctorates.
  3. The company share of AI researchers’ top papers was 31% in 2020–2024 and 8% in 1970–1974Includes University of Bonn. We estimate where the people shaping AI worked when their most-cited papers appeared: the company share was 31% in 2020–2024 and 8% in 1970–1974, and Google led all organizations in 2020–2024.
  4. Google has the highest combined h-index among AI organizationsIncludes University of Bonn. We estimate that Google holds the highest combined h-index at 8,016, while universities account for 73% of the deduplicated total across AI organizations.

Colleagues

People named in this biography, and people with dated positions at the same organization in the same years.

Sources and credits

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  1. Homotopy Hubbard Trees for post-singularly finite exponential maps arxiv.org. Checked 21 October 2026.
  2. Mathlib maintainers leanprover-community.github.io. Checked 21 October 2026.
  3. Growing Mathlib: maintenance of a large scale mathematical library arxiv.org. Checked 21 October 2026.
  4. Michael Rothgang’s homepage www2.mathematik.hu-berlin.de. Checked 21 October 2026.
  5. Chris Wendl: Abschlussarbeiten / Theses supervised mathematik.hu-berlin.de. Checked 21 October 2026.
  6. How close are we to semi-automated Mathlib bumping? leanprover-community.github.io. Checked 21 October 2026.
  7. Floris van Doorn’s Home Page florisvandoorn.com. Checked 21 October 2026.
  8. Formalizing Carleson’s Theorem in Lean arxiv.org. Checked 21 October 2026.