On Relativistic Elements of Reality

Rodolfo Gambini, Rafael A Porto

G. C. Ghirardi, Philip Pearle

Oliver Cohen, Basil J. Hiley

We examine a gedanken experiment described by Hardy, which purports to prove that the ``elements of reality'' corresponding to Lorentz-invariant observables cannot themselves be Lorentz invariant without violating quantum mechanics. We consider a number of criticisms of this proof and show that these criticisms are not convincing. We demonstrate that the contradiction, which arises in the gedanken experiment and forms the basis of Hardy's proof, has nothing to do with realism, but is a consequence of the well-known noncovariance of the reduction postulate. A reexamination of the gedanken experiment, using a more appropriate formalism, helps to clarify its implications. We conclude with a brief appraisal of realist interpretations of quantum mechanics in the relativistic domain.

Alfred Arthur Robb

Mani Lal Bhaumik

Abstract The enormous success of the Standard Model of particle physics has clearly established quantum fields as the fundamental elements of reality of the universe unveiled to us so far. Here we present for the first time a thorough derivation of the wavefunction of a nonrelativistic quantum state directly as a physically real matrix element in the quantum field theory. Consequently, the debate about whether the wavefunction is real or epistemic can now be reasonably put to rest and nonrelativistic quantum mechanics can well be on its way as a genuine theory. This significant development in our understanding of quantum mechanics has lasting theoretical and practical implications for quantum information, computing, cryptography, and relevant technology as establishing the reality of the wavefunction immediately establishes the reality of qubits.