Akiko Takeda

Improved KKT Complexity for First-Order Bilevel Optimization under Weak Lower-Level Convexity

We study deterministic first-order bilevel optimization under weak lower-level convexity, allowing nonconvex lower-level objectives and without assuming strong convexity, the Polyak-{\L}ojasiewicz condition, or an error-bound property. We consider a $\delta$-relaxed Moreau-gap constraint, with $\delta>0$, for the lower...