On Pitowsky's “The relativity of quantum predictions”

Itamar Pitowsky

Gordon N. Fleming

In a recent article Itamar Pitowsky (1991) has analyzed some measurement possibilities presented by an entangled state of three spin ½ particles. From that analysis he has concluded that the valid predictions of results of possible future measurements, made by observers who actually carry out mutually space-like separated measurements, can be incompatible with one another in the sense that their conjunction contradicts the quantum theory. From this result Pitowsky infers the inherently observer specific, or relative, character of quantum predictions as opposed to the results of actual observations or measurements, which, he claims, are covariant; i.e. (I take it) compatibly translatable from one observer to another.

Federico Laudisa

Abstract Until recently Jeffrey Bub and Itamar Pitowsky, in the framework of an information-theoretic view of quantum mechanics, claimed first that to the measurement problem in its ordinary formulation there correspond in effect two measurement problems (simply called the big and the small measurement problems), with a different degree of relevance and, second, that the analysis of a quantum measurement is a problem only if other assumptions – taken by Pitowsky and Bub to be unnecessary ‘dogmas’ – are assumed. Here I critically discuss this unconventional stance on the measurement problem and argue that the Bub-Pitowsky arguments are inconclusive, mainly because they rely on an unwarranted extension to the quantum realm of a distinction concerning the foundations of special relativity which is in itself rather controversial.

Berthold‐Georg Englert

Robert K. Clifton

Arturo Massolo, Laura Felline, Univerisità Roma

In this work we investigate the problem of locality in theories inspired by Everett’s Relative State Theory. Specifically we address the Many Worlds by Deutsch, the Many Minds Theory by David Albert and Barry Loewer and the Relational Theory by Simon Saunders, and we carry out our inquiry in view of recent work by Meir Hemmo and Itamar Pitowsky. Our aim is, on the one hand, to clarify the remarkably important points which have been put forward within Hemmo and Pitowsky work on the issue of the interpretation of probability in Many Minds, on the other hand to argue against a remark on the Relational theory, stating that the analysis carried out on the Many Minds interpretation could be applied, mutatis mutandis, to Saunders’ theory.