Let A be an algorithm with expected running time eX, conditioned on the value of some random variable X. We construct an algorithm A′ with expected running time O(eE[X]), that fully executes A. In particular, an algorithm whose running time is a random variable T can be converted to one with expected running time O(eE[lnT]), which is never worse than O(E[T]). No information about the distribution of X is required for the construction of A′.
Cite
@article{arxiv.2211.08563,
title = {The wrong direction of Jensen's inequality is algorithmically right},
author = {Or Zamir},
journal= {arXiv preprint arXiv:2211.08563},
year = {2022}
}