Cosmology in Quantum-Geometry Dynamics: Dark Matter, Dark Energy, the Hubble Tension, and the Initial State of the Universe

Cosmology in Quantum-Geometry Dynamics: Dark Matter, Dark Energy, the Hubble Tension, and the Initial State of the Universe This paper presents the first systematic standalone treatment of cosmology within Quantum-Geometry Dynamics (QGD), an axiomatic framework for physics derived from two foundational propositions: that space is discrete and composed of fundamental units called preons⁻, and that kinetic matter is composed of preons⁺ that propagate through that space by preonic leaps driven by their intrinsic momentum. From these axioms and two fundamental constants — c̃ (the quantum-geometrical momentum constant) and k (the proportionality constant between the framework's two gravitational interactions) — QGD derives a scale-dependent gravitational structure governed by a threshold distance d_Λ below which gravity is attractive and above which gravity is repulsive. I argue that this single structural feature dissolves three major unresolved problems of standard cosmology simultaneously, without invoking new particle species or a cosmological constant. Dark matter, in QGD, is not an exotic particle but the free state of preons⁺ — matter that has not yet condensed into bound composite particles. Critically, free preons⁺ are not a permanent gravitational scaffold, as CDM assumes, but the raw material from which visible matter is built. Stars and galaxies form by consuming this preonic reservoir. This yields a unified account of the full observed spectrum of galaxies: dark galaxies, in which star formation efficiency is very low and free preons⁺ remain largely unconsumed; normal galaxies, in which intermediate conversion has produced a visible structure surrounded by a preonic halo that generates flat rotation curves and gravitational lensing excess; and dark matter deficient ultra-diffuse galaxies such as NGC 1052-DF2, in which an exceptionally efficient star formation event has exhausted the local preonic reservoir, leaving a galaxy governed purely by its bound visible mass. CDM must treat these three galaxy types as separate anomalies; QGD derives all three as deterministic end-states of a single continuous process of preonic condensation. Dark energy requires no substance. The accelerated recession of distant structures follows directly from the repulsive gravitational regime beyond d_Λ. This is a material expansion — structures moving apart through fixed, static quantum-geometrical space — not a metric expansion of space itself. The cosmological constant problem does not arise in QGD because there is no vacuum energy playing a gravitational role. The Hubble tension is expected rather than anomalous. Early-universe and late-universe measurements probe different dynamical regimes of the same gravitational equation, and QGD predicts a higher inferred H₀ from late-universe probes. The paper also discusses the Son et al. (2025) supernova progenitor age-bias result — showing a 9σ tension with flat ΛCDM — as independent empirical motivation for QGD's rejection of the cosmological constant. The initial state of the universe is characterised as a maximally isotropic configuration of free preons⁺, uniformly distributed across quantum-geometrical space, from which the isotropy of the cosmic microwave background follows directly and without fine-tuning. Structure formation proceeds through gravitational redirection of preonic momentum vectors into convergent trajectories, producing streams, halos, and ultimately galaxies without requiring inflation. The paper identifies seven falsifiable predictions distinguishing QGD from ΛCDM, including an evolving dark energy equation of state, a rotation curve transition scale tied to d_Λ, the continuous galaxy dark-matter-fraction distribution as a function of star formation history, the absence of any dark matter particle, and mirror images of stellar objects as a consequence of the universe's spatial finiteness. This paper is part of the Minimal Physically Derivable Theory (MPDT) programme.