Is BPP0 equal to P0^{RP}?
Ascertain whether the class of problems with constant bounded-error randomized communication complexity (BPP0) coincides with the class computable by constant-cost deterministic protocols with oracle access to some problem in RP (P0^{RP}); i.e., prove or refute BPP0 = P0^{RP}.
References
We refer to for many other open problems regarding the complexity classes in \cref{fig:hierarchy}, and more. Is $\BPP_0 = \P_0{\RP}$?
                — Sign-Rank of $k$-Hamming Distance is Constant
                
                (2506.12022 - Göös et al., 1 May 2025) in Section 6.4 (Open Problems)