# Conditional information and hidden correlations in single-qudit states

## TL;DR

This paper explores how mutual and conditional information reveal hidden correlations in single-qudit states, drawing parallels to entanglement phenomena in systems without subsystems.

## Contribution

It introduces the concepts of mutual and conditional information for noncomposite systems and relates them to hidden quantum correlations akin to entanglement.

## Key findings

- Hidden correlations exist in single-qudit states.
- Analogies between entanglement and hidden correlations are established.
- The framework applies to both classical and quantum noncomposite systems.

## Abstract

We discuss the notions of mutual information and conditional information for noncomposite systems, classical and quantum; both the mutual information and the conditional information are associated with the presence of hidden correlations in the state of a single qudit. We consider analogs of the entanglement phenomena in the systems without subsystems related to strong hidden quantum correlations.