Quantum Reverse Shannon Theorem Simplified
Abstract
We revisit the quantum reverse Shannon theorem, a central result in quantum information theory that characterizes the resources needed to simulate quantum channels when entanglement is freely available. We derive a universal additive upper bound on the smoothed max-information in terms of the sandwiched R\'enyi mutual information. This bound yields tighter single-shot results, eliminates the need for the post-selection technique, and leads to a conceptually simpler proof of the quantum reverse Shannon theorem. By consolidating and streamlining earlier approaches, our result provides a clearer and more direct understanding of the resource costs of simulating quantum channels.
Cite
@article{arxiv.2510.04552,
title = {Quantum Reverse Shannon Theorem Simplified},
author = {Gilad Gour},
journal= {arXiv preprint arXiv:2510.04552},
year = {2025}
}
Comments
After receiving helpful feedback, I realized that the main results of my paper had already been established in two recent works, arXiv:2403.14416 and arXiv:2507.07961