[link] informational derivation of quantum theory
Giulio Chiribella’s paper, Informational derivation of quantum theory, provide a spookiness-free explanation of the foundations of quantum theory based on purification (every density matrix is the partial trace of a density matrix generated by a pure state), and further supports MWI.
“Quantum theory can be derived from purely informational principles. In particular, it belongs to a broad class of theories of information-processing that includes classical and quantum information theory as special cases. Within this class, quantum theory is identified uniquely by the purification postulate, stating that the ignorance about a part is always compatible with the maximal knowledge of the whole in an essentially unique way. This postulate appears as the origin of the key features of quantum information processing, such as no-cloning, teleportation, and error correction (see also Ref. [21]). The general vision underlying the present work is that the main primitives of quantum information processing should be derived directly from the principles, without the abstract mathematics of Hilbert spaces, in order to make the revolutionary aspects of quantum information immediately accessible and to place them in the broader context of the fundamental laws of physics.”
The paper is well-cited, but not very new, and the citations appear somewhat superficial. I tried to quickly identify the authors’ take on the only feature of Quantum Mechanics that is different between formulations: its treatment of the apparent collapse into an eigenstate during a measurement. Few argue about the part that is unitary evolution, and the process of decoherence is reasonably well established, too. It’s the last step, picking a single observed eigenstate, that is the subject of debate. Unfortunately my search for “Born”, “collapse” and “macroscopic” return zero hits, casting suspicion on the whole thing. Maybe someone can read through it in more detail and clarify?
How does it support MWI?