# Strong and epsilon-dependent converses for source or channel coding and for hypothesis testing

• Prof. Michele Wigger, Telecom Paris
• Wednesday 12 October 2022, 14:00-15:00
• MR5, CMS Pavilion A.

Abstract: This talk presents new simple strong converse proofs for basic source and channel coding setups as well as for various hypothesis testing setups. For the basic source and channel coding setups, the proofs only use a change of measure argument on the strongly typical set. This proof method is also extended to a source coding setup under relaxed expected rate constraints, in which case the minimum compression rate depends on the allowed probability of error $\epsilon$ and an $\epsilon$-dependent converse is required. In the second part of the talk we present converse proof methods for hypothesis testing setups, where the change of measure argument is not sufficient, but has to be completed with proofs of asymptotic Markov Chains. We again also consider expected resource or secrecy constraints and provide probability-of-error-dependent converse proofs under these expected constraints. Interestingly, our strong and probability-of-error-dependent converse proofs do not rely on the blowing-up lemma, on hypercontractivity arguments, or on prooving variational characterisations as in the closely related converse proofs by Tyagi and Watanabe.

This talk is part of the Information Theory Seminar series.