Existence of meta-observables and Hilbert space in the IFS-induced cyclic bouncing universe

Ascertain whether any gauge-invariant meta-observables exist and construct a well-defined Hilbert space for quantum gravity in the instant-folded-string–induced cyclic bouncing universe, where the dark-energy epoch is transient and no asymptotic future de Sitter boundary is present.

Background

The interpretation of the DP-like kernel as fundamental collapse versus effective stochasticity may depend on the global spacetime structure. In asymptotically de Sitter or Minkowski settings, observables and Hilbert space structures can sometimes be defined via asymptotic boundaries or the S-matrix.

In the IFS-induced cyclic bouncing universe, the dark energy phase is transient and there is no asymptotic future de Sitter boundary, complicating the definition of global observables (‘meta-observables’) and raising foundational questions about the existence of a well-defined Hilbert space. Resolving this would clarify whether the DP-like kernel should be treated as an objective stochastic ingredient within a causal patch.

References

In the IFS-induced cyclic bouncing universe [Itzhaki:2025gdv], the dark energy epoch is transient, and there is no asymptotic future de Sitter boundary either; from this viewpoint, it is not clear that meta-observables exist at all [Witten2001], and it is not clear how to define, even in principle, a Hilbert space.

Wavefunction Collapse in String Theory  (2603.24429 - Itzhaki, 25 Mar 2026) in Section 7 (Discussion)