Thank you very much for your comments. These are very helpful for me. In general I agree with your remarks but some points are to be discussed.

In general, it is clear that QM must be an applied probability theory and it is clear that this probability theory cannot be the Kolmogorovian probability theory.

1. The first…[Read more]

]]>I have a comment and a critical remark to your argumentation.

I shall consider the property (C1) in the more complete formulation:

(C1x) the wave function of a physical system is a complete description of the individual system.

You write “The first approach is to deny the claim (C1), and add some additional variables …”.

I think…[Read more]

I am somewhat sympathetic to the view that quantum theory should be understood in terms of some sort of non-Kolmogorovian probability theory. However, there are a couple of problems with this.

First, it is not just since 2008 that this option has existed. There are currently a few dozen competing generalized probability theories…[Read more]

]]>Turning back to your question in #3303, concerning randomness:

A central point of the paper I posted in this forum is that all of the probabilities in retrocausal quantum models can be classical/conventional in the sense that they all result from a lack of knowledge. But there are two different parts of this. First is the knowledge…[Read more]

]]>“In fact, the writing of this paper is mainly motivated by your words in your review paper. You said, “A straightforward resolution of the collapse of the wavefunction, the measurement problem, Schrodinger’s cat

and friends is one of the main advantages of psi-epistemic interpretations…. The measurement problem is not so much resolved by ps…[Read more]

I have some comments

1) The very idea of the ontological models is based on the assumption that there exists only one probability theory – the standard Kolmogorov theory. But from 2008 there exist two probability theories – the Kolmogorov (linear) probability theory and the new quadratic probability theory published in…[Read more]

]]>I am suprised that you consider the psi-epistemic view together with the idea that all observables have pre-existing values.

I understand the psi-ontic view as the standard assumption that each pure state represents the possible state of an individual system. For me the psi-epistemic view means that not all pure states represent the…[Read more]

Thanks for your interesting comments, some of which I basically agree.

But I think you misunderstood my paper. The paper does not aim to show the (realist) psi-epistemic view cannot solve the measurement problem. Rather, it only shows that the psi-epistemic view does not provide a straightforward resolution or a dissolution of the…[Read more]

]]>We have had so many discussions about this now that I am beginning to think that you are being deliberately obtuse, and trying to court controversy where there ought to be none.

Let me first note that not all ontological models solve the measurement problem, psi-epistemic or not. Some do and some don’t. Since Bohmian mechanics can be fit…[Read more]

]]>1. You catch-out the ontogical models view at a weak point. For what they call “psi-epistemic” has to do with possible overlap of ontic states in the preparation of distinct state functions. But that has nothing to do with explaining collapse on measurement. In the earlier literature, as in…[Read more]

]]>One option is…[Read more]

]]>I’m worried you’re setting up a bit of a straw man version of psi-epistemic models (you call it the “realist psi-epistemic” view, an interesting choice of words). I’d be surprised if there were many (or any!) quantum foundations people who take such a view.

Specifically, you are ascribing the following logic to anyone…[Read more]

]]>Nice post!

Regarding ontology of MWI, it appears that a preferred structure (partition into subsystems, including virtual subsystems) of the Universe is needed. Otherwise sufficiency of decoherence for defining “branches” and/or reality of “world branching” are at stake. More technically: there exist mutually irreducible,…[Read more]

]]>We shall define the concept of a truth in the situation where different theories may have the same empirical…[Read more]

]]>with best regards Aurélien

]]>with best regards Aurélien ]]>

Lev Vaidman ]]>

More specifically, I consider the problem of the ontology, the problem of the meaning of probability, and…[Read more] ]]>

(C1). the wave function of a physical system is a complete description of the system;

(C2). the wave function always evolves in accord with a linear dynamical equation, e.g. the Schrodinger equation;

(C3). each…[Read more]

Suppose that a quantum observer M is asked not with the question `Did you get a definite result to your x-spin measurement?”, but with the question `

`Did you get some definite result to your x-spin measurement,…[Read more]`

If a quantum observer being in a post-measurement superposition indeed is consciously aware of a definite result, which is…[Read more]

]]>Let us analyze Everett’s approach to quantum mechanics. This approach claims that after the a quantum measurement of spin there will be…[Read more]

]]>Let us now consider Bohm’s approach or the hidden-variables approach to quantum mechanics. As to Bohm’s approach, an analysis of the…[Read more]

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