# Comment on the Equality Condition for the I-MMSE Proof of Entropy Power Inequality

Research paper by Alex Dytso, Ronit Bustin, H. Vincent Poor, Shlomo Shamai

Indexed on: 21 Mar '17Published on: 21 Mar '17Published in: arXiv - Computer Science - Information Theory

#### Abstract

The paper establishes the equality condition in the I-MMSE proof of the entropy power inequality (EPI). This is done by establishing an exact expression for the deficit between the two sides of the EPI. Interestingly, a necessary condition for the equality is established by making a connection to the famous Cauchy functional equation.