Gravity-related spontaneous collapse in bulk matter

In the DP-model, gravity-related spontaneous wave function collapses suppress undesirable Schr\"odinger Cat states. We derive the equations of the model for the hydrodynamic-elastic (acoustic) modes in a bulk. Two particular features are discussed: the universal dominance of spontaneous collapses at large wavelengths, and the reduction of spontaneous heating by a slight refinement of the DP-model.Comment: 6p

Unique Quantum Paths by Continuous Diagonalization of the Density Operator

In this short note we show that for a Markovian open quantum system it is always possible to construct a unique set of perfectly consistent Schmidt paths, supporting quasi-classicality. Our Schmidt process, elaborated several years ago, is the $\Delta t\to 0$ limit of the Schmidt chain constructed very recently by Paz and Zurek.Comment: 8 pages REVTe

Equation and test of possible delay time of Newton force

Recently, a simple heuristic modification of the Newton potential with a non-zero delay-time $\tau_G$ has been proposed. Our modification is largely suppressed for purely gravitational interactions, it becomes relevant under non-gravitational accelerations of the sources. We illustrate how the choice $\tau_G\sim1$ms may already influence the 5th digit of G determined by Cavendish experiments. Re-evaluation of old Cavendish experiments and implementing slightly modified new ones may confirm the proposal or, at least, put a stronger upper limit on $\tau_G$.Comment: 4 pp, 2 figs, based on talk at Int. Symp. Wigner 111 - Colourful & Deep (Budapest, 11-13 Nov, 2013

Newton force from wave function collapse: speculation and test

The Diosi-Penrose model of quantum-classical boundary postulates gravity-related spontaneous wave function collapse of massive degrees of freedom. The decoherence effects of the collapses are in principle detectable if not masked by the overwhelming environmental decoherence. But the DP (or any other, like GRW, CSL) spontaneous collapses are not detectable themselves, they are merely the redundant formalism of spontaneous decoherence. To let DP collapses become testable physics, recently we extended the DP model and proposed that DP collapses are responsible for the emergence of the Newton gravitational force between massive objects. We identified the collapse rate, possibly of the order of 1/ms, with the rate of emergence of the Newton force. A simple heuristic emergence (delay) time was added to the Newton law of gravity. This non-relativistic delay is in peaceful coexistence with Einstein's relativistic theory of gravitation, at least no experimental evidence has so far surfaced against it. We derive new predictions of such a `lazy' Newton law that will enable decisive laboratory tests with available technologies. The simple equation of 'lazy' Newton law deserves theoretical and experimental studies in itself, independently of the underlying quantum foundational considerations.Comment: 7pp, 7figs, based on talk at Int. Symp. on Emergent Quantum Mechanics (Vienna, Oct 3-6, 2013

How to teach and think about spontaneous wave function collapse theories: not like before

A simple and natural introduction to the concept and formalism of spontaneous wave function collapse can and should be based on textbook knowledge of standard quantum state collapse and monitoring. This approach explains the origin of noise driving the paradigmatic stochastic Schr\"odinger equations of spontaneous localization of the wave function $\Psi$. It reveals, on the other hand, that these equations are empirically redundant and the master equations of the noise-averaged state $\hat\rho$ are the only empirically testable dynamics in current spontaneous collapse theories.Comment: Almost the published version p3-11 in "Collapse of the Wave Function", ed.: S Gao, Cambridge University Press, 201