This tag is for questions relating to what, if anything, the quantum mechanical formalism and experimental results say about the way the world works.

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3answers
306 views

How would a realist interpretation of the Mermin-Peres square look like?

How would a realist interpretation of the Mermin-Peres square with counterfactual definiteness and the existence of states prior to measurements look like?
4
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2answers
156 views

Without apparatus can we say that the system is measured(decohered) by the environment?

"Einselection" and "tridecompositional uniqueness theorem" seem to resolve the preferred basis problem. But the premise is that there are three parts in discussion.(system, apparatus, environment) ...
2
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1answer
60 views

Unitarity and measurement

I used to believed that the wavefunction collapse came from the interaction of the system we want to measure {S} with the measurement apparatus {M} : {S} undergoing a non unitary transformation, but ...
0
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1answer
62 views

Atom in a box and collapse of the wave-function

Suppose I have an atom trapped in an optically transparent box. I'm assuming the atom is bouncing off of the walls and not bonding, i.e. the center of mass of the atom experiences a square well. Now ...
0
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1answer
30 views

Entanglement Distillation - Interpretate a protocol

I have a general question to the interpretation of a enganglement distillation protocol. In general you have a set of entanglet qubit pairs in a Werner-state. Point of matter of this is that I can ...
0
votes
1answer
93 views

Are only 2 bits of information transmitted in quantum teleportation?

Prompted by the recent success in Delft, I've been reading a number of papers and articles about quantum teleportation. I'm comfortable with my understanding of most aspects but haven't found much ...
5
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0answers
122 views

Is it possible to reproduce the energy spectrum of quantum chaos using classical cellular automata?

Is it possible to reproduce the energy spectrum of quantum chaos using classical cellular automata? It's hardly impressive to reproduce harmonic oscillators.
5
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0answers
145 views

Does it make sense to speak of amplitudes of finite closed boundaries in QFT?

A example of amplitude in Relativistic Quantum Mechanics or specifically in QFT is the amplitude of a field configuration on a space-like hyper-surface of space-time to "lead" to another field ...
4
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0answers
90 views

Free Will Theorem question

The Kochen-Specker Theorem says, if I understand it correctly, that the results of spin measurements cannot be predetermined independent of measurement. They get to this conclusion by describing 33 ...
3
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0answers
89 views

Are frequency and likelihood the same across the multiverse?

My probability text distinguishes between two interpretations of probability values: the frequency of occurrence "as percentage of success in a moderately large number of similar situations" (coin ...
3
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0answers
343 views

Does the extended probability ensemble interpretation of quantum mechanics make any sense?

Gell-Mann and Hartle came up with the extended probability ensemble interpretation over here. Basically, they extended probability theory to include real numbers which may be negative or greater than ...
2
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0answers
119 views
+50

Testing Many-Worlds Interpretation (MWI) with a causality-violating configuration of “superluminal cables”

Suppose we managed to arrange a causality-violating transmission of data with hypothetical “superluminal cables” (SLC; see both links for respective descriptions) and expect, similarly to ideas ...
2
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0answers
62 views

Are universally valid possibilistic theories possible?

This is a spin-off of the following question: Are Thomas Breuer's subjective decoherence and Scott Aaronson's freebits with knightian freedom the same things in essence? Given that Thomas ...
2
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0answers
192 views

Double slit experiment and entanglement

Just wondering, what would happen in this experiment. In the experiment you would first have two entangled particles. Then you fire one of the particles, lets say "Particle A", at a double slit ...
2
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0answers
107 views

How can the pre-measurement be fulfilled?

In the decoherence program, the pre-measurement refers to the evolution in which the system and apparatus form a Schmidt state. In Maximilian Schlosshauer's review article(2005), I read "the linearity ...
2
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0answers
129 views

Uncertainty Principle and Bohmian mechanics

The Uncertainty Principle is a relationship between measurements of pairs of attributes, position and momentum, as well as energy and time. Perfect precision of one attribute's measurement leads to a ...
2
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0answers
51 views

Is it possible to detect subjective decoherence? If yes, how?

In his paper from 1994 Thomas Breuer describes a phenomenon of subjective decoherence (p. 43). I wonder whether it can be measured, and if yes, how. I also wonder whether it would allow to create an ...
2
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0answers
93 views

How to explain Tsirelson's inequality using extended probabilities?

How to explain Tsirelson's inequality using extended probabilities? Some people have tried explaining the Bell inequalities using extended probabilities. For instance, a pair of entangled photons ...
2
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0answers
60 views

Are there any connections between James–Stein estimator and quantum mechanics?

Very nice statement from wiki: When three or more unrelated parameters are measured, their total MSE can be reduced by using a combined estimator such as the James–Stein estimator; whereas when ...
1
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0answers
49 views

Hardy's paradox (see the article “Quantum Mechanics, Local Realistic Theories, and Lorentz-Invariant Realistic Theories”)

Does this thought-experiment (Phys. Rev. Lett., Vol. 68, No. 20, page 2981, year 1992) represent a proof against Bohm's interpretation of the quantum mechanics? The analysis of Hardy rules out local ...
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0answers
41 views

Many Worlds or Infinite Worlds?

Looking at the latest paper to deal with the topic: where it purports to show that QM can be recovered from the interactions of a multitude of Newtonian worlds, we have the following statements: ...
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0answers
46 views

Is relational QM experimentally distinguishable from standard QM?

Some people advocate for relational quantum mechanics, which is an interpretation (or at least Wikipedia calls it an interpretation) of QM where quantum states are thought of as representing a ...
1
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0answers
114 views

Why are cosmic conspiracies considered undesirable in quantum interpretations?

Quantum interpretations like superdeterminism, nonlocal hidden variables, etc. are regularly dismissed by the vast majority of physicists because they require "cosmic conspiracies" which can ...
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0answers
64 views

What is a potential in De-Broglie-Bohm theory?

As I have so far understood, the De-Broglie-Bohm theory is based on two equations: The Schrödinger equation. The Guiding equation of the De-Broglie-Bohm theory. In the Schrödinger equation (as ...
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0answers
58 views

Is there any “fundamental” uncertainty to the timing of the Big Bang?

I wondered whether, under the probabilistic interpretations of QM, the timing of the Big Bang (or perhaps any other historical event) is fundamentally as uncertain as (or: like) other (e.g., future) ...
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0answers
81 views

What is the difference between Cramer and Vaidman?

Two very interesting new papers on arXiv last night by Lev Vaidman and friends lead me to ask about the differences between Cramer's transactional interpretation of quantum mechanics (TIQM) and the ...
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0answers
77 views

Hamiltonian matrix propertu

A professor made an statement to prove the variational theorem: Because the Hamiltonian (H operator of quantum physics) is diagonal in its own eigenfunction, the terms in $\left \langle \Phi _{m} ...
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0answers
166 views

Consistent histories and Bohm mechanics, many worlds in disguise?

This was posted on here in someone's Phys.SE answer: No, in the many worlds interpretation, every parallel universe is real, but in consistent histories, once you choose your projection operators, ...
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0answers
106 views

Bohmian Quantum Mechanics diffusion

About one year ago I attended a pretty interesting seminar of Nino Zanghì on the actual state of Bohmian mechanics. Now, during my undergraduate studies, I didn't have the possibility to take a class ...
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0answers
115 views

Identifying fragments when there is a superposition of fragments in quantum Darwinism

In Zurek's theory of quantum Darwinism, information about the pointer states of a system imprint themselves upon fragments of the environment carrying records about the state of the system. ...
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0answers
33 views

Arrow of Time in Information transfer

I am writing a sci-fi script and need some legitimate theory to back up a central story element (so there's no real world application): Could there be a logically consistent theory supporting the ...
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0answers
30 views

How would the transactional interpretation “bootstrap”

I have an interest in quantum physics and have been trying to educate myself here, other places on line and by reading "The Quantum Universe". During this process I became quite drawn to the ...
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0answers
51 views

Bell's inequality

For a project, I'm planning to study Bell's inequality, which as far as I can gather is taken to rule out hidden variable theories of QM. I'm looking for recommendations of decent sources which derive ...
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0answers
51 views

Quantum entanglement, principle of locality and speed of light

I know it's a newbie question but I was wondering about how the principle of locality and the speed of light's limit fit with the phenomena of quantum entanglement? I've read that, due to Bell's ...
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0answers
49 views

Could the space outside the observable universe be entangled?

The title really says it all. One follow-up question is: How could one falsify this?
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0answers
36 views

Hamiltonian (temperature?) and frame of reference

So we can define a particle by defining its kinetic and potential energy, knowing that we can get a wavefunction describing a particle. But the kinetic energy involves motion, and motion can be ...
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0answers
33 views

Choices within the many-worlds interpretation

I should preface this question by pointing out that I am a completely amateur scientist and may be missing something very obvious. I've been learning about the many-worlds interpretation recently and ...
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0answers
100 views

Test for Many Worlds Hypothesis

If one actually ran an experiment similar to the Schrodinger's cat thought experiment, and ran it enough times (with the same cat) to get the confidence interval good enough, could one say that ...
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0answers
55 views

Realistic interpretations of quantum entanglement: Are there alternatives to the “Transactional Interpretation”?

Quantum entanglement bridges space and time: entangled particles show correlations independently of where and when they are measured. This is most evident in "delayed choice quantum eraser" ...
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0answers
24 views

Representation of a Signal and its evolution via Quantum System

I am a total beginner in the field of Quantum Mechanics. So, the question I am asking may be a silly one. So kindly give me possible answers or advice for modifications. Recently I am learning the ...
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0answers
306 views

Does the Delayed Choice Quantum Eraser experiment prove consciousness causes collapse?

https://www.youtube.com/watch?v=H6HLjpj4Nt4 This question comes from the video above. If you don't want to watch the video, I'll cut to the chase. Essentially, it claims the Delayed Choice Quantum ...
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0answers
72 views

Born rule and Feynman propagators

Let us assume that we want to describe the full process of photon emission by electron A and absorption by electron B. Therefore electron B must be on the forward lightcone of electron A. In the ...
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0answers
89 views

The status of unobservable quantum mechanical predictions

Orthodox quantum mechanics intrinsically requires an observer - since the only connection from the mathematical formalism to physical reality is through the measurement axiom (probability of observing ...
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0answers
186 views

Is the Copenhagen interpretation still valid?

"The secret lives of photons revealed" - physicsworld.com. It seems that this experiment violates the Copenhagen interpretation. Is it still valid? Can you please give me more insight on this ...
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0answers
53 views

Does the nonlocality of the preferred basis mean QM is nonlocal?

Take the Mach-Zehnder interferometer as an example. A photon passes through a beam splitter, is reflected off mirrors, and interferes with itself at another half-silvered mirror. No measurements or ...
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0answers
142 views

Question regarding the Bohm interpretation

I tryed to understand the Bohm interpretation and this is what picture appeared to me. Please tell me if I understood something incorrectly. All particles have definite positions and follow ...
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0answers
241 views

Hardy's Theorem

https://perimeterinstitute.ca/psi_portal/sites/perimeterinstitute.ca.psi_portal/files/hardyphysrevlett.68.2981.pdf Some researchers in Bohmian Mechanics have hoped to make the theory Lorentz ...