General Relativity and the Probability Interpretation of Everett’s Relative State Formulation

One of the primary conceptual difficulties facing the multiple worlds interpretation (MWI) of quantum mechanics is the interpretation of the Born rule measure as a probability. Given that each world in the MWI is typically envisioned as being equally “real,” a more natural rule would be to assign each of the N branches associated with a measurement the equivalent probability 1/N , rather than the probability |a| prescribed by the Born rule. This approach, the “alternate projection postulate” (APP), has been paid scant attention, however, since it leads to predictions that contradict those of standard quantum mechanics. In this paper, a further modification of the MWI is presented that not only incorporates the aesthetic advantages of the APP, but also is compatible with the predictions of quantum mechanics. This further modification involves an alternativemethod of enumerating branches that satisfies what is termed here the “Born identity,” according to which there is not a single branch associated with a given experimental outcome, but rather more than one branch, with each branch being physically distinct and the number of branches being proportional to |a|. In place of the assumption of the Born identity, however, a feasibility argument for the derivation of the Born identity from more fundamental field-theoretic principles (such as those provided by general relativity) is sought. In this manner, it is proposed that quantum statistics may be derived from a purely classical (general relativistic) foundation without injecting the Born rule – either directly or in disguised form – as an independent postulate.