We exhibit an $n$-bit communication problem with a constant-cost randomized protocol but which requires $n^{\Omega(1)}$ deterministic (or even non-deterministic) queries to an Equality oracle. Therefore, even constant-cost randomized protocols cannot be efficiently "derandomized" using Equality oracles. This improves on several recent results and answers a question from the survey of ... more >>>

We continue the study of half-duplex communication complexity, a model introduced in [HIMS18] and further studied in [DISSU21], in which each player can either send a bit or listen in each round, similarly to communication over a walkie-talkie.
We prove improved upper bounds for the Inner Product function in the ... more >>>