  In the last few years, the theory of decentralized distributed convex
optimization has made significant progress. The lower bounds on communications
rounds and oracle calls have appeared, as well as methods that reach both of
these bounds. In this paper, we focus on how these results can be explained
based on optimal algorithms for the non-distributed setup. In particular, we
provide our recent results that have not been published yet and that could be
found in details only in arXiv preprints.
