Conserved active information
Yanchen Chen, Daniel Andrés Díaz-Pachón
TL;DR
To address NFLT-driven limitations of average information measures, the paper introduces active information $I^+$ and its conservation counterpart $I^\oplus$. It provides a measure-theoretic formulation of $I^+$ and derives a closed-form baseline regime for $I^\oplus$ under a uniform baseline, showing when external information is needed versus when global order can emerge through internal redistribution; The results are illustrated with Bernoulli distributions, Markov chains, and cosmological fine-tuning and are connected to potential applications in search, optimization, AI, and estimation. Overall, the work offers a principled framework to quantify information balance across the entire search space, extending beyond KL and providing a tool for diagnosing when problem-specific knowledge yields net conservation or requires external input.
Abstract
We introduce conserved active information $I^\oplus$, a symmetric extension of active information that quantifies net information gain/loss across the entire search space, respecting No-Free-Lunch conservation. Through Bernoulli and uniform-baseline examples, we show $I^\oplus$ reveals regimes hidden from KL divergence, such as when strong knowledge reduces global disorder. Such regimes are proven formally under uniform baseline, distinguishing disorder (increasing mild knowledge from order-imposing strong knowledge. We further illustrate these regimes with examples from Markov chains and cosmological fine-tuning. This resolves a longstanding critique of active information while enabling applications in search, optimization, and beyond.
