Looped spacetime cosmology: a closed-time framework for quantum gravity and cosmology

Looped Spacetime Cosmology (LSC) explores whether black hole interiors and the cosmological origin may be linked by a single global spacetime structure. The framework posits a compact S3×S1 topology in which astrophysical black hole trapped regions are globally identified with a common Big Bang hypersurface so that classical terminal curvature endpoints are replaced (at the level of induced data) by a compact global completion. As a minimal realization of nonterminal high-curvature behavior, we employ effective dynamics inspired by loop quantum cosmology (LQC), without assuming a specific ultraviolet completion. The resulting consequences are conditional: if the identification is dynamically admissible, then (i) classical singularities may be avoided in an effective description via bounded-density transitions; (ii) information carried by infalling degrees of freedom need not terminate at a singular boundary but can be globally accounted for on the identified hypersurface, contingent on an isometric mapping across the transition region; (iii) fine-grained entropy can remain globally conserved, while coarse-grained observers still experience an emergent arrow of time; and (iv) compact topology provides a setting in which infrared-regulated vacuum contributions can be consistent with a small late-time cosmological constant in representative models. LSC is formulated as a falsifiable hypothesis rather than a completed theory. Its empirical program is organized as hierarchical tests: Tier I gates probe sign-fixed curvature/topology consistency and can falsify the framework outright; Tier II tests constrain dark-sector realizations without negating the global identification if Tier I survives; and Tier III probes transition-region microphysics (e.g., model-dependent compact-object phenomenology) and is logically downstream. Near-term scrutiny is provided by spatial curvature and topology constraints, population-level compact-object spin statistics, and cross-channel consistency checks using cosmic microwave background (CMB) and large-scale structure data.