I am a final year PhD student in algebraic and computational number theory, under the supervision of Prof. Samir Siksek. My current research interests include studying the arithmetic of abelian varieties and Galois representations, with a particular interest in studying the reduction behaviour of elliptic and hyperelliptic curves and their Jacobians. I also often enjoy playing around with various aspects of analytic number theory.

E-mail address: robin.visser@warwick.ac.uk or robin.visser@matfyz.cuni.cz

Background: After finishing my B.Sc. (Hons) degree at Stellenbosch University in 2018, I completed my MASt (Part III) at the University of Cambridge in 2020, where I also wrote a short essay on large prime gaps. For more information on my background, see my CV.

Teaching:

• Teaching assistant for MA124 Mathematics by Computer (Term 1, 2023/24)
• Supervisor to first year maths undergraduates (2022/23)
• Teaching assistant for MA4H8 Ring Theory (Term 2, 2022/23)
• Teaching assistant for MA252 Combinatorial Optimisation (Term 2, 2022/23)
• Teaching assistant for MA3E1 Groups & Representations (Term 1, 2022/23)
• Supervisor to first year maths undergraduates (2021/22)
• Teaching assistant for MA4H9 Modular Forms (Term 2, 2021/22)
• Teaching assistant for MA3A6 Algebraic Number Theory (Term 1, 2021/22)
• Supervisor to first year maths undergraduates (2020/21)

Writing:

• Sums of two units in number fields (joint with Magdaléna Tinková and Pavlo Yatsyna) (arXivLink opens in a new window), February 2025.
• The Effective Shafarevich Conjecture (draft).
• Curves with few bad primes over cyclotomic $\mathbb{Z}_\ell$-extensions (joint with Samir Siksek) (published versionLink opens in a new window) (arXivLink opens in a new window), Algebra Number Theory 19 (2025), no. 1, 113–141.
• Potential good reduction of hyperelliptic curves (arXivLink opens in a new window), January 2022.
• Calculating L-values of elliptic curves twisted by Grossencharacters (draft), 2022.
• First year projects on Reduction of Hyperelliptic Curves and L-values of Twisted Elliptic Curves, September 2021.
• A short mini-project on the Abel-Jacobi map, January 2021.
• Some of my (very rough) Part III notes on Elliptic Curves, Modular Forms, Algebraic Number Theory, Analytic Number Theory.
• Computing dimensions of spaces of modular forms (pdf), BSc project, 2018.

Talks:

• Sums of two units in number fields (slides), March 2025.
• Computing genus 2 curves over $\mathbb{Q}$ whose Jacobians have good reduction away from 2 (slides), June 2024.
• The Effective Shafarevich Conjecture (slides), February 2024.
• Murmurations in Arithmetic (slides), January 2024.
• Gaps between primes (slides), October 2023.
• Abelian surfaces with good reduction away from 2 (slides), September 2023.
• Kronecker's limit formula and L-functions of elliptic curves with CM (Euler Systems seminar) (notes), September 2023.
• Curves with few bad primes over cyclotomic $\mathbb{Z}_\ell$-extensions (slides), July 2023.
• A survey of applications to Matomäki-Radziwiłł's theorem (slides), March 2023.
• Genus 2 Isogeny Cryptography (slides), December 2022.
• Eichler-Shimura and the Shimura representation (Mazur's Torsion Theorem) (linkLink opens in a new window), November 2022.
• Sums of three cubes (slides), November 2022.
• Hilbert's Tenth Problem (slides), October 2022.
• Jacobians (Mazur's Torsion Theorem) (linkLink opens in a new window), May 2022.
• Cluster pictures for hyperelliptic curves (slides), May 2022.
• A proof of Bary-Soroker & Kozma’s irreducibility theorem (slides), February 2022.

Other random stuff:

• My Erdős number is 3, but more importantly, my Erdős lap number is 3 (proof).
• My OEIS contributionsLink opens in a new window.
• A very handy video tutorialLink opens in a new window on how to start writing.

(click here for a more human photo)