Information bottleneck solutions for stable variable relationships

On the Information Bottleneck for Stable Variables

Information Theory

Summary

This paper studies a way to simplify information when two related data sources are connected with certain types of noise called stable noise. The authors found an exact way to encode this information using combinations of linear functions and stable noise, extending previous knowledge from the simpler Gaussian case. They also show that these encoding methods work best when compressing a lot of data but don't always reach the best possible performance otherwise. Their work generalizes well-known results and could help in understanding information compression beyond common assumptions.

What this means in practice

A theory result. No direct application yet.

Authors

Dongmin Park, Jihad Fahs, Mohamad Assaad

Abstract

We consider a generalization of the Gaussian information bottleneck problem to jointly stable variables $X$ and $Y$. Specifically, for $X = Y + A$, where $A$ is stable and independent of $Y$, we find optimal stochastic linear encoders of the form $T = kX + N$, $N$ being stable and independent of $X$. We characterize the linear stable information bottleneck in closed-form and its critical value. Furthermore, we show that, except for the Gaussian case, such stochastic linear encoders are strictly suboptimal, however asymptotically optimal at large compression rate. Our linear solution recovers the Gaussian information bottleneck for jointly Gaussian variables.