The quantum formalism and its main interpretations

Mladen Domazet

Ever since the beginning of development of Quantum Mechanics there was a metaphysical division between the “macro” world as described in “everyday language” and the “micro” world described by quantum formalism (especially due to entanglement of two or more logically conflicting states). A discussion is offered of the need to reunite these arbitrarily divided worlds through an overview of the main interpretations of the formalism. Bohr’s Copenhagen interpretation, as well as the problems it faces due to EPR thought experiment, is presented in greater detail. It is claimed that Bohr’s answers to the said experiment demand more than a restriction of everyday descriptive metaphysics, when describing phenomena at the micro-level. Thus, the special place Bohr’s interpretation takes among other interpretations of the formalism is forfeited. It is also shown that MacKinnon’s more detailed schema aiming to connect the theoretical and everyday language cannot be applied to EPR conclusions and Bohr’s reply to those. MacKinnon’s own modifications of the “everyday language” induced by the mathematical conclusions of Quantum Mechanics are considered too radical and too coarse to take the vacated special place among formalism interpretations.

Andrei Yu. Khrennikov

Yu. I. Ozhigov, Luigi Accardi, Guillaume Adenier +5 more

I describe the main ideas of constructive physics and its role for the probability interpretation of quantum theory. It is shown how the explicit probability space for quantum systems gives the formal representation of entanglement and decoherence.

Simon Friederich

This chapter reviews the quantum theoretical formalism and sketches its foundational problems. The main function of this chapter is to establish common ground for the interpretive discussions which follow, not to provide a comprehensive introduction to quantum theory. 6 Its first section recapitulates the essential aspects of the Hilbert space formalism of quantum mechanics, the second section covers the textbook account of measurement and measurement collapse, and the third and final section outlines the quantum theoretical treatment of many-component systems and explains the concept of quantum entanglement. Further introductory material is provided in the Appendices A, B, and C, all of which cover important no-go theorems for the interpretation of the theory. These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.