Résumé : Let $E / \mathbb{Q}$ be a non-CM elliptic curve and let $\mathcal{E}$ denote the collection of all elliptic curves geometrically isogenous to $E$. That is, for every $E^{\prime} \in \mathcal{E}$, there exists an isogeny $\varphi: E \rightarrow E^{\prime}$ defined over $\overline{\mathbb{Q}}$. Motivated by ties to Serre's Uniformity Conjecture, we will discuss the problem of identifying minimal torsion curves in $\mathcal{E}$, which are elliptic curves $E^{\prime} \in \mathcal{E}$ attaining a point of prime-power order in least possible degree. Using recent classification results of Rouse, Sutherland, and Zureick-Brown, we obtain an answer to this question in many cases, including a complete characterization for points of odd degree.

This is joint work with Nina Ryalls and Lori Watson.

Keywords : elliptic curves; Galois representations; modular curves