 
Summary: Failure of Standard Quantum Mechanics for the
Description of Compound Quantum Entities
Diederik Aerts and Frank Valckenborgh
Center Leo Apostel (CLEA) and Foundations of the Exact Sciences (FUND)
Department of Mathematics, Brussels Free University
Pleinlaan 2, 150 Brussels, Belgium
diraerts@vub.ac.be, fvalcken@vub.ac.be
Abstract
We reformulate the `separated quantum entities' theorem, i.e. the theorem that proves that two
separated quantum entities cannot be described by means of standard quantum mechanics, within
the fully elaborated operational GenevaBrussels approach to quantum axiomatics, where the basic
mathematical structure is that of a State Property System. We give arguments that show that the
core of this result indicates a failure of standard quantum mechanics, and not just some peculiar
shortcoming due to the axiomatic approach to quantum mechanics itself.
1 Introduction
We reformulate the theorem that has been proved by one of the authors [1, 2] that shows that standard
quantum mechanics cannot described the situation of separated quantum systems with the operational
GenevaBrussels approach of State Property Systems. We also give arguments that show that the result of
this theorem indices a failure of standard quantum mechanics, and not just a peculiarity of the axiomatic
approach itself. To make the whole consistent and self contained we also reformulate in a precise way
