It has been debated whether quantum mechanics and special relativity are compatible and whether there is a preferred Lorentz frame if they are incompatible. Bell’s theorem is an important cornerstone, but it does not give us a definite answer due to the existence of supplementary assumptions or theoretical loopholes; there are unitary quantum theories which evade Bell’s theorem.
In recent years, there has been stimulating discussion about superobservers, which might help settle the important issue of whether unitary quantum theories are compatible with special relativity. This online workshop aims to highlight the existing debates and address the controversies.
Workshop Date: Thursday, August 1, 2019 to Sunday, September 1, 2019
Advisory Board: Lajos Diósi, Arthur Fine, Gordon N. Fleming, Olival Freire Jr., Sheldon Goldstein, Robert B. Griffiths, Hans Halvorson, Richard A. Healey, Basil J. Hiley, Don Howard, Peter J. Lewis, Roger Penrose, and Maximilian Schlosshauer.
Based on the successful previous workshops, this online workshop will be more selforganized. Every participant, after logging in, may create a topic in the workshop forum on his own, which gives a concise introduction to his ideas to be discussed. Then other participants can leave comments and participate in the discussions by text chat in the forum.
All IJQF members are welcome.

editor replied to the topic Quantum theory is incompatible with relativity: A proof beyond Bell's theorem in the forum 2019 International Workshop: Beyond Bell's theorem 3 years, 3 months ago
Thanks, Ruth!

Ruth Kastner replied to the topic Quantum theory is incompatible with relativity: A proof beyond Bell's theorem in the forum 2019 International Workshop: Beyond Bell's theorem 3 years, 3 months ago
Reply to Aurelien: No, RTI has emphatically nothing to do with Bohr or the Copenhagen interpretation, which I criticize and reject here:https://arxiv.org/abs/1601.07545
If you read my publications, you will find that I assign objective physical reality to quantum states and the advanced states. You seem to be implicitly assuming that for something…[Read more] 
Ruth Kastner replied to the topic Quantum theory is incompatible with relativity: A proof beyond Bell's theorem in the forum 2019 International Workshop: Beyond Bell's theorem 3 years, 3 months ago
To Shan: That is correct. The collapse occurs with respect to projection operators (outer products), not with respect to kets. That is, from absorber response to each component we get two weighted projection operators:Psi1><Psi1 and Psi2><Psi2, where each is weighted by the Born Rule based on the prepared state. So if the prepared state was…[Read more]

Richard Healey replied to the topic Beyond Bell? in the forum 2019 International Workshop: Beyond Bell's theorem 3 years, 3 months ago
Thanks, Jerry.
A little clarification:
You sayHealey and Gao agree Alice expects the result “+1” only 50% of the time
.
In her situation prior to each of her individual measurements Alice expects each of its possible results to be equally likely. But in her situation prior to the whole sequence of her future measurements Alice expects eit…[Read more]

Federico Comparsi started the topic A REEXAMINATION OF THE EPR ARGUMENT AND BELL'S THEOREM in the forum 2019 International Workshop: Beyond Bell's theorem 3 years, 3 months ago
In this paper I will reexamine the EPR argument and Bell’s theorem putting particular emphasis on the relevant points for the analysis of the problem of locality (milestone of general relativity and classical field theories). I will clearly state the logical and mathematical
assumptions present in these cornerstones of foundations of q…[Read more] 
editor replied to the topic Beyond Bell? in the forum 2019 International Workshop: Beyond Bell's theorem 3 years, 3 months ago
Thanks for your useful comments, Jerry!

Jerry Finkelstein replied to the topic Beyond Bell? in the forum 2019 International Workshop: Beyond Bell's theorem 3 years, 3 months ago
In the case in which Bob’s measurement occurs after Alice’s, Richard
Healey and Shan Gao agree that Alice would expect to obtain the result
“+1” about 50% of the time. Let’s think about what Bob would expect
Alice’s results to be. I will suppose, to make the story more
definite, that Bob’s own measurement has the result “1”.
Consider first…[Read more] 
Aurelien Drezet replied to the topic Quantum theory is incompatible with relativity: A proof beyond Bell's theorem in the forum 2019 International Workshop: Beyond Bell's theorem 3 years, 3 months ago
Dear Ruth, thanks a lot . Still I don’t think that you are completely right : your view is like the one of Heisenberg for the passage from the potential to the actual and when you wrote ” “Collapse” in RTI is actualization of a single invariant spacetime interval from a set of nonspatiotemporal set of possibilities, represented by wei…[Read more]

editor replied to the topic Quantum theory is incompatible with relativity: A proof beyond Bell's theorem in the forum 2019 International Workshop: Beyond Bell's theorem 3 years, 3 months ago
Thanks, Ruth. So, the collapse is not the superposition psi1 + psi2 randomly becomes psi1 or psi2 for the forwardpropagating state or the the backwardpropagating state?

Ruth Kastner replied to the topic Quantum theory is incompatible with relativity: A proof beyond Bell's theorem in the forum 2019 International Workshop: Beyond Bell's theorem 3 years, 3 months ago
Dear Aurelien, RTI does not require any preferred foliation; it does not require any future boundary condition. It is not a hidden variable approach nor does it rely on a notion that measurement outcomes are ‘already there’ in the future–i.e. it is not a block world ontology. I understand that the original TI may have seemed to imply that, but…[Read more]

Ruth Kastner replied to the topic Quantum theory is incompatible with relativity: A proof beyond Bell's theorem in the forum 2019 International Workshop: Beyond Bell's theorem 3 years, 3 months ago
Thanks Shan. In RTI the quantum state Psi> is fully ontic. But the advanced state <Psi is also fully ontic, so RTI is a different animal from the usual ‘quantum interpretation.’ This is why it is not subject to the dilemma you pose. It has real ontic collapse, but the collapse is not with respect to just a forwardpropagating quantum state. In…[Read more]


Nikolay L. Chuprikov started the topic Mysteries of QM result from the fact that this theory is not yet finished in the forum 2019 International Workshop: Beyond Bell's theorem 3 years, 3 months ago
Briefly:
In particular, quantum theory missed asymptotic superselection rules which restrict the action of the superposition principle in some scattering problems for closed systems with asymptotically free dynamics.
In details:
As is known, when discussing Bell inequalities, it is very important to identify all (explicit and implicit)…[Read more]

Aurelien Drezet replied to the topic Quantum theory is incompatible with relativity: A proof beyond Bell's theorem in the forum 2019 International Workshop: Beyond Bell's theorem 3 years, 3 months ago
Dear Ruth, thank you for answering. I agree that an approach like the one of Sutherland requires two boundaries (one in the past and the other in the future) and that the foliation needed is arbitrary. However, the choice could have a cosmological meaning breaking the symmetry. Anyway, I think that this is the same for all…[Read more]


editor replied to the topic Quantum theory is incompatible with relativity: A proof beyond Bell's theorem in the forum 2019 International Workshop: Beyond Bell's theorem 3 years, 3 months ago
Thanks, Ruth! I will need more time to understand your RTI. As far as I see, your RTI does not assume a real collapse of the real wave fucntions. Maybe in RTI the wave function is not ontic?

Ruth Kastner replied to the topic Quantum theory is incompatible with relativity: A proof beyond Bell's theorem in the forum 2019 International Workshop: Beyond Bell's theorem 3 years, 3 months ago
Thanks Aurelien, I am indeed aware of the Sutherland model and you are correct that it is covariant, except perhaps for the final boundary condition which has to be defined in a particular frame (but it’s a matter of debate as to whether that ‘really’ fixes a preferred frame). Other than the final B.C., the model preserves full Lorentz covariance.…[Read more]

Aurelien Drezet replied to the topic Lorentzinvariant, retrocausal, and deterministic hidden variables in the forum 2019 International Workshop: Beyond Bell's theorem 3 years, 3 months ago
the link for this work is https://arxiv.org/abs/1904.08134

Aurelien Drezet started the topic Lorentzinvariant, retrocausal, and deterministic hidden variables in the forum 2019 International Workshop: Beyond Bell's theorem 3 years, 3 months ago
We review several nogo theorems attributed to Gisin and Hardy, Conway and Kochen purporting the impossibility of Lorentzinvariant deterministic hiddenvariable model for explaining quantum nonlocality. Those theorems claim that the only known solution to escape the conclusions is either to accept a preferred reference frame or to abandon the…[Read more]

Aurelien Drezet replied to the topic Quantum theory is incompatible with relativity: A proof beyond Bell's theorem in the forum 2019 International Workshop: Beyond Bell's theorem 3 years, 3 months ago
Dear Ruth, I would like to add a comment concerning the role of preferred frames in a quantum ontology and in connection with retrocausality. It is indeed possible to develope Bohmian like model without preferred frames. There is one recent approach by Sutherland but I also recently proposed a different one…[Read more]
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