Horizon-Maintenance Dark Energy: A Pre-Euclid Bridge Note from Finite Distinguishability

Official website: distinctiontheory.orgPublic portal for the start guide, papers, claim status, failure registry, prior-art boundary, and citation resources. Canonical GitHub repository:https://github.com/yiningwu-research/Distinction-Theory This document registers FDS-X1, a high-risk physical bridge note in the Distinction Theory / Active Finite Distinction Systems (DT/FDS) research programme. It is intended as a pre-Euclid timestamp for a falsifiable horizon-maintenance interpretation of dark energy. The central bridge claim is that if a cosmological horizon is treated as a finite distinguishability boundary, then its maintenance scale naturally takes the form ρHM ∼ H2MPl2, equivalently ρHM/ρPl ∼ (ℓP/RH)2 ∼ 10-122. The note interprets this scaling as a horizon-maintenance cost rather than as a conventional quantum-field-theoretic vacuum-energy sum or a standard holographic dark-energy model. The purpose of this note is not to present a completed cosmological model. It does not derive general relativity, quantum gravity, the cosmological constant, or the Standard Model from first principles. Instead, it registers a high-risk bridge hypothesis: finite distinguishability at cosmological horizons may account for the observed dark-energy scale and may imply a constrained class of dynamical dark-energy behavior. The pre-Euclid prediction registered here is that the physical horizon-maintenance component should behave non-phantom, with wphys(z) ≥ -1 and late-time approach toward w = -1. Apparent phantom crossing in effective observational reconstructions is treated as compatible only if it arises from sector mixing, parameterization artifacts, systematics, or incomplete mapping between fitted variables and the underlying physical horizon-maintenance component. The note includes explicit demotion and falsification conditions. The strict horizon-maintenance version is demoted if future Euclid, DESI, Roman, CMB, or supernova constraints lock dark energy to a constant w = -1 with no evidence of density evolution. It is falsified if observations establish robust, unavoidable, physical phantom behavior w < -1 that cannot be interpreted as an effective reconstruction artifact. This record is intended for priority, auditability, and future comparison with Euclid and other dark-energy survey results. It should be cited as a pre-registered high-risk bridge note, not as a completed replacement for ΛCDM.