Hi! I’m Robin, a postdoctoral researcher in algebraic and computational number theory at Charles University in Prague, Czechia. I completed my PhD under the supervision of Samir Siksek at the University of Warwick. My research interests include the statistical properties of totally real fields, the arithmetic of abelian varieties and Galois representations, and 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: robin.visser@matfyz.cuni.cz
Background. After finishing my BSc (Hons) at Stellenbosch University in 2018, I completed the 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.
Publications
- Sums of two units in number fields (with Magdaléna Tinková and Pavlo Yatsyna). Math. Z. 312 (2026), no. 2, Paper No. 39. [published] [arXiv]
- Repellent properties of perfect powers on partition functions: a heuristic approach (with Summer Haag, Praneel Samanta, Swati, Holly Swisher and Stephanie Treneer). Res. Math. Sci. 13 (2026), no. 2, Paper No. 40. [published] [arXiv]
- Rectangle partitions generalizing integer partitions (with Krystian Gajdzica and Maciej Zakarczemny). Ann. Comb. (2026). [published] [arXiv]
- Curves with few bad primes over cyclotomic $\mathbb{Z}_\ell$-extensions (with Samir Siksek). Algebra Number Theory 19 (2025), no. 1, 113–141. [published] [arXiv]
Preprints
- On integers that are representable as the sum of two units (with Volker Ziegler), August 2026. [arXiv]
- Asymptotics of $n$-universal lattices over number fields (with Dayoon Park, Pavlo Yatsyna and Jongheun Yoon), October 2025. [arXiv]
- Potential good reduction of hyperelliptic curves, January 2022. [arXiv]
Theses
- The Effective Shafarevich Conjecture. PhD thesis, University of Warwick, 2024. [published] [pdf]
- Large Gaps Between Primes. Part III (MASt) essay, University of Cambridge, 2020. [pdf]
- Computing dimensions of spaces of modular forms. BSc thesis, Stellenbosch University, 2018. [pdf]
Other writing
- Calculating L-values of elliptic curves twisted by Grossencharacters, 2022. [draft]
- First year PhD project on 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 and analytic number theory. More detailed notes are on the Part III page.
- A third-year undergraduate project on derivations of triangular algebras, 2017.
Talks
- Higher genus theory and unramified quadratic extensions of biquadratic fields [slides, handout]
- Asymptotics of $n$-universal lattices [slides, handout]
- Probably purple partition patterns prefer prohibiting perfect powers [slides]
- Bounds on the minimal ranks of $n$-universal lattices [slides]
- Sums of two units in number fields [slides]
- Computing genus 2 curves over $\mathbb{Q}$ whose Jacobians have good reduction away from 2 [slides]
- The Effective Shafarevich Conjecture [slides]
- Murmurations in arithmetic [slides]
- Gaps between primes [slides]
- Abelian surfaces with good reduction away from 2 [slides]
- Kronecker’s limit formula and L-functions of elliptic curves with CM (Euler Systems seminar) [notes]
- Curves with few bad primes over cyclotomic $\mathbb{Z}_\ell$-extensions [slides]
- A survey of applications of Matomäki–Radziwiłł’s theorem [slides]
- Genus 2 isogeny cryptography [slides]
- Eichler–Shimura and the Shimura representation (Mazur’s Torsion Theorem) [video]
- Sums of three cubes [slides]
- Hilbert’s tenth problem [slides]
- Jacobians (Mazur’s Torsion Theorem) [video]
- Cluster pictures for hyperelliptic curves [slides]
- A proof of Bary-Soroker and Kozma’s irreducibility theorem [slides]
Teaching
- Course instructor for NMAL431 Advanced Algebraic Number Theory
- Course instructor for NMAL431 Advanced Algebraic Number Theory
- Teaching assistant for MA124 Mathematics by Computer
- Supervisor to first-year maths undergraduates
- Teaching assistant for MA4H8 Ring Theory
- Teaching assistant for MA252 Combinatorial Optimisation
- Teaching assistant for MA3E1 Groups & Representations
- Supervisor to first-year maths undergraduates
- Teaching assistant for MA4H9 Modular Forms
- Teaching assistant for MA3A6 Algebraic Number Theory
- Supervisor to first-year maths undergraduates
Other things
- My Erdős number is 3, but more importantly my Erdős lap number is also 3 (proof).
- My OEIS contributions.
- My LMFDB contributions.
- A very handy video tutorial on how to start writing.
- A list of some papers I’m currently reading.
- My old Warwick webpage can be found here.
