Interesting thread. I operate under the assumption of an ontic wavefunction. I also agree with RUTA that these frankenstein particles don't actually provide an empirical distinction that circumvents prior arguments. However, I am impressed with its potential to articulate the distinctions between these opposing viewpoints.
Dmitry67 said:
No, because in deterministic interpretations there is no 'probability' - at all.
In principle yes, in practice 'probability' is unavoidable in the formalism. Even classical thermodynamics unavoidably relies on 'probability' in the formalism. Even a basic dice role can only be predicted by probability. My personal sense, given my assumptions, is that the wavefunction is an amalgamation of both ontic and epistemic elements. In the dice case an ensemble can be trivially decomposed into real and epistemic parts. In the wavefunction case even our notions of what constitutes a fundamental physical property fails to maintain a distinct identity like dice, as if the realness we empirically percieve in the things around us are epistemic rather than ontic. The only class of theories I know to get around this considers measured properties as emergent, rather than inate.
Local theories that maintain local realism and escape both the Bell and Kochen-Specker Theorems exploit contextuality. Consider how we operationally define Einstein Realism in the context of BI. In essense we take some measurable value, often labeled Alice and Bob, and use them as a proxy for ontic values. Thus any localy realistic theory that doesn't violate these theorems must contextualize these measured values as emergent global properties of an underlying physics. This seems to imply that the wavefunction is, at least in part, a real wave of some sort, with emergent properties we measure and mistakenly assume are inate to the ontic parts. Relational QM is predicated on a similar viewpoint. A lot of abstract models have been formulated in an attempt to demonstrate feasibility, but to date no such model uniquely or fully recovers the formalism of QM.
Although this approach to circumventing the no-go theorems works in principle, it hasn't been demonstrated to be feasible to empirically replicate QFT. Thus my presumptions are just that, presumptions. Yet any argument that attempts to articulate a case for the wavefunction being real is of interest.
Here's the objection I would pose to RUTA's argument. It's true we don't have to view the path integral Z as involving paths, but this presumes the variable we associate with the path is itself not an ontic entity. Fair enough, as this so far would be true for both CI and the contextual relational interpretation mentioned above. Yet what is implied by presuming no ontic entities are involved in defining these properties? It implies that none of the everyday things we interact with are fundamentally ontic in nature. Most of us I presume reject this right or wrong, but once we reject epistemic properties without ontic elements of some sort to define them how do we then reconcile certain physical variables not requiring them. It seems silly to presume that certain physical properties lack an ontic basis at some level yet still cling to the notion that our everyday world contains ontic entities.
Now certainly there exist many variables that merely encode our state of knowledge, thus require no ontic basis in and of themselves. Yet, if we presume the Universe has an ontic basis, even these variables have ontic underpinnings as some state of knowledge about the ontic elements. Now if we try to maintain an ontic Universe while avoiding any ontic realness contained in the wavefunction, this is only possible by professing ignorance of where the ontic elements are contained, which we are if they exist. Furthermore, any objection to the assumption that the wavefunction has real elements depends on our ignorance to merely claim that we don't have to consider variable X real, which is true, but X can be moved to whatever argument is being made, such as the path integral. Thus it becomes an argument from ignorance. CI requires this very real ignorance to justify moving the goal post at will to maintain cogency without explicitly rejecting the Universe has ontic underpinnings.
It is my opinion that in order to avoid ontic realness associated with the wavefunction at any level requires assuming the Universe or any part of it needs no ontic basis. As a personal preference I'm betting the wavefunction contains real components of some sort, even if no particular variable we use to describe it is explicitly ontic in itself.
I know I'm rambling... maybe I had too much coffee this morning.
