Bounded Negativity Conjecture
Prove that for every smooth projective surface X, there exists an integer b(X) greater than or equal to zero such that every curve C contained in X satisfies C^2 greater than or equal to -b(X).
References
Let $X$ be a smooth projective surface. Then there exists an integer $b=b(X)\ge0$ such that $C2\ge-b$ for every curve $C\subseteq X$.
— Bounded cohomology property on Jacobian elliptic surfaces with simplicial Mori cones
(2609.00592 - Li, 1 Sep 2026) in Introduction, Conjecture 1.1