Arbeitsgruppe Geometrie, Topologie und Gruppentheorie

Dr. Sira Busch

Mathematisches Institut
Universität Münster
Orléans-Ring 10
48149 Münster

Zimmer: 110.004
Email: s_busc16 [at] uni-muenster.de
Personal web page: https://sirabusch.de

Pronouns: Any. If you cannot choose, then they/them.
You may address me by name; i.e. "Sira Busch" instead of "Ms Busch" or "Frau Busch" etc.

Research interests:

I am interested in group theory, geometry and combinatorics.

Preprints and publications:

A Point-Line Approach to the Nonexistence of Buildings of Types H₃ and H₄. Sira Busch, Journal of Geometry, vol. 117, no. 1, paper no. 18, doi.org/10.1007/s00022-026-00799-4 (2026). For the preprint verison cf. arXiv:2507.02441.

A Characterization of Lines in Finite Lie Incidence Geometries of Classical Type. Sira Busch and Hendrik Van Maldeghem, Discrete Mathematics, vol. 349, no. 2, doi.org/10.1016/j.disc.2025.114711 (2026). For the preprint verison cf. arXiv:2408.02413.

Groups of Projectivities and Levi Subgroups in Spherical Buildings of Simply Laced Type. Sira Busch, Jeroen Schillewaert, Hendrik Van Maldeghem, Journal of Group Theory, doi:10.1515/jgth-2024-0185 (2026). For the preprint verison cf. arXiv:2407.09226.

Groups of Projectivities in Spherical Buildings of Non-Simply Laced Type. Sira Busch and Hendrik Van Maldeghem, Beiträge zur Algebra und Geometrie / Contributions to Algebra and Geometry, doi.org/10.1007/s13366-026-00839-9 (2026). For the preprint verison cf. arXiv:2507.02441.

On the Moufang Condition for Polar Spaces. Sira Busch. For the preprint verison cf. arXiv:2507.02441.

Lines and Opposition in Lie Incidence Geometries of Exceptional Type. Sira Busch and Hendrik Van Maldeghem. For the preprint verison cf. arXiv:2602.01110.

On Wiegold's Conjecture for the Small Ree Groups. Sira Busch, Mark Pengitore, Jeroen Schillewaert, Hendrik Van Maldeghem. For the preprint verison cf. arXiv:2510.06479.

Theses:

Groups of Automorphisms of Spherical Buildings.
PhD thesis (2025), 436 pages, summa cum laude,
doi:10.17879/10908475556, you can find a pdf here: PDF.
Gruppenkubisierung und ein Ergebnis Sabidussis.
Group cubization and a result of Sabidussi.
Master's thesis (2020)
Teilmengen mit Toren und Projektionen in metrischen Räumen und Gebäuden.
Gated subsets and projections in metric spaces and buildings.
Bachelor's thesis (2017)

Talks:

07/05/2026, tba, Séminaire Algèbre ICJ, Université Claude Bernard Lyon 1, France.
04/05/2026, tba, Groups and Actions seminar, Université Paris-Saclay, Département de Mathématiques d'Orsay, France.
29/04/2026, tba, GGT seminar, University of Bonn, Germany.
06/02/2026, Icosahedral buildings, Bielefeld-Münster Seminar on Groups, Geometry and Topology, Bielefeld University, Germany.
08/09/2025, Non-existence of H₃ and H₄ buildings, Buildings 2025, UCLouvain, Louvain-la-Neuve, Belgium.
29/03/2025, Linien, Das Grüppchen, Christian-Albrechts-Universität zu Kiel, Germany.
24/02/2025, Lines in geometries associated with finite buildings, Group Theory Seminar at UCLouvain, Louvain-La-Neuve, Belgium.
13/12/2024, Lines in geometries associated with finite buildings, Joint meeting of the NZMS, AustMS and AMS Conference, Session Groups and Geometry, University of Auckland, New Zealand.
15/11/2024, Lines in geometries associated with finite buildings, Magic Square Seminar, Universiteit Gent, Belgium.
10/09/2024, Projectivity Groups of Spherical Buildings, Integral Structures in Geometry and Representation Theory, Session Groups and Geometry, Opening conference of CRC-TRR 358 of Bielefeld and Paderborn University, Paderborn, Germany.
13/06/2024, Projectivity Groups of Spherical Buildings, Geometry and Groups Seminar, Ruprecht-Karls-Universität Heidelberg, Germany.
19/04/2024, Projectivity groups of spherical buildings, Oberseminar Algebra und Geometrie, Heinrich Heine University Düsseldorf, Germany.
24/02/2024, Die Moufang-Eigenschaft in Polarräumen, Das Grüppchen, Martin-Luther-Universität Halle-Wittenberg, Germany.
09/02/2024, The Moufang Property in Polar Spaces, Bielefeld-Münster Seminar on Groups, Geometry and Topology, Münster University, Germany.
18/01/2024, Spherical Buildings and the Moufang Property, PostGrad Seminar, University of Auckland, New Zealand.
16/01/2024, The Moufang Property in Polar Spaces, Algebra and Combinatorics Seminar, University of Auckland, New Zealand.
05/12/2023, Constructing automorphisms and showing the Moufang property for projective planes and generalized quadrangles in polar spaces, Magic Square Seminar, Universiteit Gent, Belgium.
07/07/2023, Buildings as Generalizations of Projective Spaces – Visualizing the Moufang Property, HaJe MaDre, Martin-Luther-Universität Halle-Wittenberg, Germany.
24/03/2023, Spherical Buildings, Das Grüppchen, Christian-Albrechts-Universität zu Kiel, Germany.
03/2022, Group Cubization, Oberseminar Group Geometry, Otto-von-Guericke-Universität Magdeburg, Germany.

Education and Employments:

2026 and beyond: Postdoc at Ghent University under the supervision of Prof. Dr. Hendrik Van Maldeghem (April–October 2026), and postdoc at the University of Iceland starting October 2026.
2022–2026: PhD student at the University of Münster under the supervision of Prof. Dr. Linus Kramer, funded by the Dissertation Plus Scholarship of the Claussen-Simon-Stiftung, the Diversity Support Fellowship of the Cluster of Excellence Mathematics Münster, and Fachbereich Mathematik und Informatik FB 10 of the University of Münster.
2021–2022: I worked as an author and wrote a book about how norms and stereotypes prohibit equality. Find it here.
2020–2021: I worked as a software engineer. I was interested in and worked with: Go, Python, Java, Apache Spark, Apache Kafka, SQL, Terraform, REST, Containerisation, Bash, Git, Github.
2017–2020: Master of Science Mathematics, University of Münster, minor subject philosophy.
2013–2017: Bachelor of Science Mathematics, University of Münster, minor subject philosophy.

Research Stays & Visits:

Nov 30–Dec 22 2024: Visit to the University of Auckland, New Zealand; joint research with Jeroen Schillewaert and Hendrik Van Maldeghem.
Sept 18–Nov 28 2024: Research stay at Ghent University, Belgium; joint research with Hendrik Van Maldeghem.
Jan 07–Jan 20 2024: Visit to the University of Auckland, New Zealand; joint research with Jeroen Schillewaert and Hendrik Van Maldeghem.
Nov 05–Dec 22 2023: Research stay at Ghent University, Belgium; joint research with Hendrik Van Maldeghem.

Teaching and Tutoring:

Teaching assistant for Finite Group Theory (WS25/26)
Teaching assistant for Foundations of Analysis, Topology and Geometry (SS24)
Tutor for Analysis I (WS19/20)
Tutor for Linear Algebra II (SS19)
Tutor for Mathematics For Physicists III (WS16/17)

* Tutor meaning a person who gives exercise sessions and grades the solutions of the students. Teaching assistant meaning a person who provides the exercises, solution sketches and coordinates between the tutors and the professor.

Miscellaneous:

I was organizer of the Buildings 2024 conference.
I won the ANZIAM (Australia and New Zealand Industrial and Applied Mathematics) prize for Best Poster at the joint meeting of the NZMS, AustMS and AMS.
I am a member of the Fachgruppe Gender, Diversity and Sustainability in Mathematics of the German Mathematical Society since the 23rd of June 2023 and contact person for questions regarding trans identity and neurodiversity.
I am a math ambassador of the Stiftung Rechnen since 2017.