Hi Richard –
Thank you for your response to my earlier posting. I had understood that
you were agreeing with Shan that Alice would expect 50% of her results to
be “+1”; this clarification eliminates my worry about a contradiction
between the expectations of Alice and Bob. Alice would say that each
individual result has a probability of 50%…[Read more]

Thanks, Ruth!

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]

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]

Thanks, Jerry.

A little clarification:
You say

Healey 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]

Thanks for your useful comments, Jerry!

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]

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 non-spatiotemporal set of possibilities, represented by wei…[Read more]

Thanks, Ruth. So, the collapse is not the superposition psi1 + psi2 randomly becomes psi1 or psi2 for the forward-propagating state or the the backward-propagating state?

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]

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 forward-propagating quantum state. In…[Read more]

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]

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?

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]

the link for this work is https://arxiv.org/abs/1904.08134