The Born rule serves as a postulate assumed by the founders of the field to convert information about quantum objects into probabilities for specific outcomes. For over a century, the probabilistic nature of quantum mechanics has remained a puzzle for researchers, particularly regarding the measurement problem.
Zhang spent approximately two years examining five of the most significant derivations of the rule to test if they could be built on deterministic principles. The analysis concluded that a concept called additivity is indispensable to all derivations of the Born rule.
Smerzi noted that while making assumptions explicit is necessary, understanding why nature obeys them provides a derivation with deeper physical meaning. Smerzi stated he would not interpret the findings as closing the door to a deeper explanation of quantum probabilities, but rather as a reason to continue the search.
Zhang said a small chance that the Born rule could be put on deterministic foundations still exists.
