ref: http://backreaction.blogspot.com/2019/12/the-path-we-didnt-take.html
*Rethinking Superdeterminism* S. Hossenfelder, T.N. Palmer https://arxiv.org/pdf/1912.06462.pdf The path integral approach to superdeterminism [S. Donadi, S. Hossenfelder, in preparation] rests on the observation that the Feynman path integral has a future input dependence already, which is the upper time of the integration. However, in the usual path integral of quantum mechanics (and, likewise, of quantum field theory), one does not evaluate what is the optimal future state that the system can evolve into. Instead, one posits that all of the future states are realized, which results in a merely probabilistic prediction. The idea is then to take a modified path integral for the combined system of detector and prepared state and posit that in the underlying theory the combined system evolves along merely one possible path in state space that optimizes a suitable, to-be-defined, function. This function must have the property that initial states which evolve into final states containing superpositions of detector eigenstate states are disfavoured, in the sense that they do not optimize the function. Instead, the optimal path that the system will chose is one that ends up in states which are macroscopically classical. One gets back normal quantum mechanics by averaging over initial states of the detector. This approach solves the measurement problem because the system does deterministically evolve into one particular measurement outcome. Exactly which outcome is determined by the degrees of freedom of the detector that serve as the “hidden variables”. Since it is generically impossible to exactly know all the detector’s degrees of freedom, quantum mechanics can only make probabilistic predictions. The challenge of this approach is to find a suitable function that actually has this behaviour. @philipthfit -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/5882dc16-5dc1-4e90-9af0-9152f67d6d58%40googlegroups.com.
