Part I : Trans-Generational Continuity of Dark Matter and Dark Energy / Part II : terminal universe and the chorus trigger for the Big Bang / Part III: The Universe's Memory — Closure, Contraction, and Rebirth

Version 4. 0 Part III: The Universe's Memory - Closure, and How It Opens Again - The inconsistencies identified in Part II are resolved by replacing its interpretational framework with the dynamical formulation introduced in Part III, providing a consistent and minimal description of the system. The dark sector, which constitutes about 95% of the universe, should not be treated as two unrelated unknowns called dark matter and dark energy. This work redefines them as two inheritance sectors: FM (Fundamental Matter), the structural carrier of cosmic matter, and FE (Fundamental Energy), the residual vacuum energy left after pair-annihilation and observed as dark energy. Their self-consistent fixed point governs cosmic evolution. Through HEX (Horizon Entropy Exchange), entropy is transferred between black holes and the de Sitter horizon, driving the universe toward its final state, SFC (Space Folding Collapse). In this framework, the Big Bang is not an absolute beginning but an inward transition of a previous cosmic structure, and cosmic evolution is understood as inheritance rather than creation from nothing. Abstract Part I We call it dark matter because we cannot see it, and dark energy becausewe do not understand it. Both names reflect our limitations rather than thenature of the things themselves. This paper proposes that what isconventionally termed dark matter is more precisely Fundamental Matter (FM) — the basic form of matter, interacting solely through gravity — andthat what is conventionally termed dark energy is more preciselyFundamental Energy (FE) — the basic expansive property of space, symmetric to gravity. We propose that what is conventionally termed dark matter is moreprecisely Fundamental Matter (FM) — the basic form of matter, interactingsolely through gravity — and that dark energy is more preciselyFundamental Energy (FE) — the basic expansive property of space, symmetric to gravity. Both are entropic invariants: FM occupies themaximum entropy state available to gravity-only matter; FE has zeroentropy as a uniform property of space. This entropic inertness is thestructural reason why FM and FE persist across cosmological transitionswhile ordinary matter does not. The cosmological constant problemdissolves once vacuum energy (matter sector, extractable via Hawkingradiation) and FE (spatial property, not extractable) are recognised ascategorically distinct — reducing the 10¹²² discrepancy to a boundarycondition, not a fine-tuning problem. Baryonic asymmetry emerges as astructural consequence of the inherited inhomogeneous FM distribution. The fine structure constant α is derived from the FM/FE energy inventory asa fixed-point relation, recovering the observed value to seven significantfigures. The framework makes falsifiable predictions testable with JWST, Euclid, DESI, and LISA. Part II Part I established that Fundamental Matter (FM) and Fundamental Energy (FE) persist across cosmological generations while ordinary matter (OM) cycles through black holes via Hawking radiation. Part II extends thisframework to the terminal state of the universe. We propose that the finaluniverse — in which all OM has been converted to FM and only a singleclass of black holes remains — satisfies two distinct trigger conditions thattogether initiate a new Big Bang: a geometric condition, in which externalFE volume exceeds internal volume, and a thermodynamic condition, inwhich black hole entropy converges on horizon entropy. These twoconditions constitute a chorus trigger: they need not arrive simultaneously, but both must be met. We further propose that our universe is the firstcosmological generation (n = 0), and derive that OM depletion reachescompletion within approximately 4 generational cycles under f = 0. 844, derived from the observed OM fraction. The framework requires no inflatonfield, no external fine-tuning, and no appeal to structures beyond FM, FE, and classical thermodynamics. Fine-tuning is not imposed from outside —each generation, the universe converges upon its own constants throughthe self-referential structure of FM, FE, and α. Part III The terminal universe satisfies two conditions — geometric andthermodynamic — that together constitute the Chorus Trigger. Whatfollows is the mechanism by which the universe closes, contracts, and opens again. We propose that Fundamental Energy (FE), identified as the Hawking quantum vacuum at the cosmologicalhorizon, undergoes pair production at the de Sitter boundary; atthe cosmological horizon, pair production manifests vacuumproperties (matter and antimatter), converting to FM state —which then enters the trans-horizon layer, a physicallyinaccessible but physically real space admitting only gravity-only matter. Following the Chorus Trigger, this trans-horizon FMundergoes Horizon Equivalent Exchange (HEX): FM traverses thecosmological horizon inward — material state preserved, noentropic exchange — returning to Domain 1. As trans-horizon FMreturns, the accessible FE volume shrinks. The de Sitter horizoncontracts. The approximately 18 causally isolated terminal blackholes — one per de Sitter bubble, N = (Rₒbs / RdS) ³ ≈ 18 —converge toward a black-hole-dominated asymptotic terminalconfiguration. The Big Bang is not an explosion into externalspace. It is an inward event — an entropic seeding phasetransition into pre-existing, pre-defined space between theterminal black-hole-dominated state and the contracting cosmichorizon. The universe closes upon itself, and opens again. Thisis the universe's memory.