Jonathan Fruchter

📧 fruchter [at] math.uni-bonn.de 1.27, Mathematisches Institut der Universität Bonn, Endenicher Allee 60, 53115

Postdoctoral research associate at the University of Bonn, working in Giles Gardam’s team.

I completed my DPhil at the University of Oxford, under the supervision of Martin Bridson. Before that, I obtained my master’s degree at the Hebrew University of Jerusalem under the supervision of Zlil Sela.

My research is in geometric group theory and my work explores connections between geometry, topology and profinite rigidity. I also work with group rings of infinite groups, with a focus on the Kaplansly conjectures.
In addition, I am interested in model theory and the first-order theory of groups.

Research papers:

Virtual homology of residually free groups and profinite rigidity of direct products, with Ismael Morales.
Preprint (arXiv:2209.14925)

Limit groups over coherent right-angled Artin groups are cyclic subgroup separable.
Michigan Mathematical Journal 73-5 (2023): 909-923 (journal version) (arXiv:2101.10458)

Formal solutions and the first-order theory of acylindrically hyperbolic groups, with Simon André.
Journal of the London Mathematical Society 105-2 (2022), 1012-1072 (open access)

Teaching:

In 2022-2023 I was a Stipendiary Lecturer in Pure Mathematics at Exeter College (University of Oxford), teaching A2: Metric Spaces and Complex Analysis in Michaelmas ‘22-23 and A4: Integration in Hilary ‘23.
Before that I was a tutor and a TA at the University of Oxford, the Hebrew University of Jerusalem and Reichman University (IDC Herzliya). I taught linear algebra, discrete mathematics, general topology, set theory, mathematical logic, infinite groups, geometry of surfaces, group theory and integration.

Other things that I like:

I really enjoy it when mathematics and visual arts come together.

In ‘20-21 I volunteered with Multaka and co-produced the Precious and Rare: Islamic Metalwork from The Courtauld exhibition at the History of Science in Oxford.
I made a short animated video explaining symmetry for the exhibition, and you can see me talking about the exhibition here. I also made a computer programme which allowed exhibition visitors to generate their own symmetric patterns inspired by Islamic art (feel free to email me if you made a cool design and want to share):

(compatible with mobile devices - drag the point on the big triangle)