Timo Keller

activity

20232026

most citedTowards a classification of isolated

j

-invariants

1 citations · 1 across the 2 of their papers we have counts for

collaborators

3 papers

math.NT2026

Semi-stable models, local heights and quadratic Chabauty for $X_{0} (N)^{*}$

Nikola Adžaga, Maarten Derickx, Timo Keller

Quadratic Chabauty computations for $X_{0} (N)^{*}$ are complicated by local height contributions at primes of bad reduction. For squarefree $N$ , we explain a strategy for constructing…

math.NT2025

Rational points on $X_{0} (N)^{*}$ when $N$ is non-squarefree

Sachi Hashimoto, Timo Keller, Samuel Le Fourn

Let $N$ be a positive integer and $X_{0} (N)^{*}$ be the quotient of the modular curve $X_{0} (N)$ by its full group of Atkin-Lehner involutions. Elkies conjectures that the rational point…

math.NT2023★ 1 cited

Towards a classification of isolated $j$ -invariants

Abbey Bourdon, Sachi Hashimoto, Timo Keller +5

We develop an algorithm to test whether a non-CM elliptic curve $E / Q$ gives rise to an isolated point of any degree on any modular curve of the form $X_{1} (N)$ . This builds…

Semi-stable models, local heights and quadratic Chabauty for X0​(N)∗

Rational points on X0​(N)∗ when N is non-squarefree

Towards a classification of isolated j-invariants

Semi-stable models, local heights and quadratic Chabauty for $X_{0} (N)^{*}$

Rational points on $X_{0} (N)^{*}$ when $N$ is non-squarefree

Towards a classification of isolated $j$ -invariants