We review results concerning the problem of ‘Stability of Matter’. Non-relativistic, relativistic quantum mechanics as well as matter interacting with classical fields is discussed and the strategies of the various proofs of these results is given in some detail. This is followed by a short discussion of the corresponding problem of matter interacting with the radiation field.

Ever since we have been in the possession of quantum theories without observers, such as Bohmian mechanics or the Ghirardi–Rimini–Weber (GRW) theory of spontaneous wave function collapse, a major challenge in the foundations of quantum mechanics is to devise a relativistic quantum theory without observers. One of the difficulties is to reconcile nonlocality with relativity. I report about recen...

Relativistic Nonlocality is applied to experiments in which one of the photons impacts successively at two beam-splitters. Thereby a time series with 2 non-before impacts can be produced with beam-splitters at rest. It is discussed whether such an experiment may allow us to decide between Quantum Mechanics (QM) and Relativistic Nonlocality (RNL).

Form factors of a simple system have been calculated in various forms of relativis-tic quantum mechanics, using a single-particle current. Their comparison has shown large discrepancies. The comparison is extented here to instant-and front-form calculations in unusual kinematics as well as to a point-form approach inspired from the Dirac's one (based on a hyperboloid surface). It is found that ...

Gunnar Nordström died just a few years before the advent of quantum mechanics. It is is very interesting, but of course futile to speculate how he would have contributed to the new subject. His early attempts to increase the number of space dimensions [1] could very well have been very important for him when the spin degrees of freedom were understood. The birth of quantum mechanics in the 1920...

Does there exist a purely quantum mechanical carrier of the imprints of gravitation? The motivation for considering this question arises from the following historical scenario: Suppose a time traveller from today visited Einstein in 1907, when he had the “happiest thought of his life”, just in time before Einstein actually started on the path which led towards his formulation of gravitation (ge...

Chapter 1: Jeremy Butterfield, “On Symplectic Reduction in Classical Mechanics.” Chapter 2: Gordon Belot, “The Representation of Time and Change in Mechanics.” Chapter 3: David Malament, “Classical Relativity Theory.” Chapter 4: Michael Dickson, “Non-Relativistic Quantum Mechanics.” Chapter 5: Klaas Landsman, “Between Classical and Quantum.” Chapter 6: Jeffrey Bub, “Quantum Information and Comp...

We compute in a relativistic way the time-of-arrival and the traversal time through a region of a free particle with spin 1 2 . We do this by applying the relativistic extension of the Event-Enhanced Quantum Theory which we have presented in a previous paper. We find a very good coincidence of the results of our formalism and the results obtained by using classical relativistic mechanics. PACS ...

This paper describes a tentative relativistic quantum mechanics approach inspired by Dirac's point-form, which is based on the physics description on a hy-perboloid surface. It is mainly characterized by a non-standard relation of the constituent momenta of some system to its total momentum. Contrary to instant-and front-form approaches, where it takes the form of a 3-dimensional δ(· · ·) funct...