Unbounded rank (or maximal rank) of elliptic curves over Q
Ascertain whether the supremum of Mordell–Weil ranks of elliptic curves over the rational field Q is infinite; if it is finite, determine the exact largest possible Mordell–Weil rank of an elliptic curve over Q.
References
Even for $K := Q$, it is unknown whether one can find curves with arbitrarily large rank or, alternatively, what the largest possible rank should be.
— Elliptic curves of rank one over number fields
(2505.16910 - Koymans et al., 22 May 2025) in Section 1.1 (Introduction: Ranks of elliptic curves)