Resource theories of knowledge

TL;DR

This paper broadens the scope of resource theories in physics by including knowledge-based descriptions, relating different resource frameworks, and deriving subsystem structures from global theories, thereby enabling new applications across various domains.

Contribution

It generalizes resource theories to incorporate agents' knowledge, relates different resource descriptions, and derives subsystem structures from global theories, expanding their applicability.

Findings

Extended resource theories to include knowledge descriptions

Related micro and macroscopic thermodynamics within a unified framework

Derived subsystem structures from global theories for broader applications

Abstract

How far can we take the resource theoretic approach to explore physics? Resource theories like LOCC, reference frames and quantum thermodynamics have proven a powerful tool to study how agents who are subject to certain constraints can act on physical systems. This approach has advanced our understanding of fundamental physical principles, such as the second law of thermodynamics, and provided operational measures to quantify resources such as entanglement or information content. In this work, we significantly extend the approach and range of applicability of resource theories. Firstly we generalize the notion of resource theories to include any description or knowledge that agents may have of a physical state, beyond the density operator formalism. We show how to relate theories that differ in the language used to describe resources, like micro and macroscopic thermodynamics. Finally, we take a top-down approach to locality, in which a subsystem structure is derived from a global theory rather than assumed. The extended framework introduced here enables us to formalize new tasks in the language of resource theories, ranging from tomography, cryptography, thermodynamics and foundational questions, both within and beyond quantum theory.