Quantum decoherence Definition and 21 Threads

I was thinking about this paper (https://arxiv.org/abs/1405.0298) where the authors argue that there wouldn't be dynamical quantum fluctuations in a De Sitter space as fluctuations would be static once all perturbative radiation escapes the horizon (in the case that the Universe has a finite...

Quantum decoherence. and the emergence of continuous space/time and gravity In another forum I have experienced a lot of combative dialogue asserting that continuous time/space is a property of the smallest Quantum scale. My present knowledge indicates this not true, and that the goal of the...

Suppose there are two entangled particles A and B, separated by a few miles or light years. If the spin for particle A is observed, then from my understanding, A will experience quantum decoherence. And now we can be sure that B will have the opposite spin since B is entangled with A. Assuming...

I have tried to study decoherence theory for a while now, and it does seem to answer why classical distributions arise, instead of quantum ones.Is this fully accepted as an explanation for a classical world out of a quantum one?

What happens to the other possible outcomes after decoherence has been finalized? Where do they go?

So I whilst understanding basics of some quantum phenomena like superposition, tunnelling, fluctuations etc I happened to watch the movie "Coherence" where there's a scientifically unsatisfactory reference to quantum decoherence. What exactly is this concept?

I've seen a couple of lectures by Penrose where he describes an experiment to test superposition of physical location of a very small, but macroscopic object. I can't find a reference to it online, but the experiment involved sending a photon through a half-mirror, and depending on the route...

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Experiment description: Let us have a slight modification of the famous thought experiment, in which the cat is killed only if a particle decay is detected in a fixed time interval, say from 0 to 1 s. Let the box with the cat, the deadly device, and the radioactive sample with the detector be an...

If yes, then how is it any different from other facts of causality, and why is there a puzzle? Can one not simply view quantum particle changes as the causal interaction between subatomic and macroscopic objects, yielding certain processes of behavior under physical law, depending on the...

I keep hearing about things like "quantum decoherence" and the notion that measurement doesn't need a conscious observer. However, I haven't really seen these topics discussed in any of the textbooks I've used (mostly on the level of Griffiths and higher). I haven't even seen a reference to...

Am I reading some more recent articles on quantum gravity correctly that seem to be implying that a coherent particle is not subject to gravity? If you have a coherent C70 buckyball molecule (see Zeilinger - Update: "Matter-wave interferometer for large molecules", Jan. 2002), the force of...

So I understand that as the number of entangled particles increases, observable quantum mechanical properties decrease to the extent that the mass of particles collectively loses its wave-particle character and behaves classically. In other words, the particles' collective position-space...

I read up on quantum decoherence however the math was not explained clearly can someone explain it to me

From time to time I hear that Quantum Decoherence can address the measurement problem only when accompanied by deBroglie-Bohm theory(dBB) (or any hidden variable theory? or MWI?). I want to know why is that? Also, I saw some papers recently(e.g. this) that prove dBB is incompatible with QM...

does quantum decoherence mean object is leaking into the environment and actually exists permentely as a superstion of states?

Hi all, My limited knowledge of quantum decoherence leads me to believe that it can be demonstrated experimentally via rather humble apparatus involving low power lightbulbs, a few sensors, & some plywood with holes in & some switches etc. I was just wondering what kind of pattern you get if...

Why doesn't it occur constantly and only when 'interacting" with another larger scale phase space? Why does an electron for example require a large scale human readable detector in the way to interact that way with the environment when the environment is there anyway? Air, Dust, etc. -- Also...

I've been reading a bit about quantum decoherence today. But I'm stuck on the following contradictions: I think I've read somewhere that after the wave function collapses, it will resume its normal superpositioned state soon after measurement. But according to quantum decoherence a...

So if you remember, Loschmidt's paradox is about "Loschmidt's paradox, also known as the reversibility paradox, is the objection that it should not be possible to deduce an irreversible process from time-symmetric dynamics" ( http://en.wikipedia.org/wiki/Loschmidt's_paradox ) My question is...

Here, in Saint Petersburg, Russia I open a box with a Schroedinger cat I get immediately decoherenced so I see only one cat - dead or alive How soon that decoherence 'hits' you in the US? Photons can not travel directly to another part of the globe, they get absorbed/reemitted, losing the...