642 research outputs found
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 limit of the Schmidt chain constructed very
recently by Paz and Zurek.Comment: 8 pages REVTe
Note on Possible Emergence Time of Newtonian Gravity
If gravity were an emergent phenomenon, some relativistic as well as
non-relativistic speculations claim it is, then a certain emergence time scale
tau_? would characterize it. We argue that the available experimental evidences
have poor time resolution regarding how immediate the creation of Newton field
of accelerated mass sources is. Although the concrete theoretical model of
gravity's `laziness' is missing, the concept and the scale tau_? ~ 1ms, rooted
in an extrapolation of spontaneous wave function collapse theory, might be
tested directly in reachable experiments.Comment: 2pp, essentially revised, clarified, concretized version accepted in
PL
Comments on "Objectification of classical properties induced by quantum vacuum fluctuations"
We argue that in standard quantum electrodynamics radiative corrections do
not lead to decoherence of unexcited atomic systems. The proposal of Santos
relies upon deliberate switching on and off the vacuum interactions.Comment: 4 pages Latex, 21-June-199
Calculation of X-Ray Signals from Karolyhazy Hazy Space-Time
Karolyhazy's hazy space-time model, invented for breaking down macroscopic
interferences, employs wave-like gravity disturbances. If so, then electric
charges would radiate permanently. Here we discuss the observational
consequences of the radiation. We find that such radiation is excluded by
common experimental situations.Comment: 7 pages, PlainTe
Quantum linear Boltzmann equation with finite intercollision time
Inconsistencies are pointed out in the usual quantum versions of the
classical linear Boltzmann equation constructed for a quantized test particle
in a gas. These are related to the incorrect formal treatment of momentum
decoherence. We prove that ideal collisions would result in complete momentum
decoherence, the persistence of coherence is only due to the finite
intercollision time. A corresponding novel quantum linear Boltzmann equation is
proposed.Comment: 5p
The gravity-related decoherence master equation from hybrid dynamics
Canonical coupling between classical and quantum systems cannot result in
reversible equations, rather it leads to irreversible master equations.
Coupling of quantized non-relativistic matter to gravity is illustrated by a
simplistic example. The heuristic derivation yields the theory of
gravity-related decoherence proposed longtime ago by Penrose and the author.Comment: 9pp, extended version of invited talk at Fifth International Workshop
DICE2010 (Castello Pasquini/Castiglioncello/Tuscany, Sept. 13-17, 2010
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
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 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
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 .Comment: 4 pp, 2 figs, based on talk at Int. Symp. Wigner 111 - Colourful &
Deep (Budapest, 11-13 Nov, 2013
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