The new OCO bound resolves the open problem posed by Cevher et al. (2023) and Hait et al. (2025) and improves upon the best-known O((d log T)^(2/3) T^(1/3)) upper bound

also significantly improving upon the best-known $\mathcal{O}((d\log T)^{2/3}T^{1/3})$ upper bound and resolving the open problem posed by Cevher et al. [2023], Hait et al. [2025]

http://arxiv.org/abs/2608.25182v1