Cosmological Viability of an Information-Coupled Two-Field Model: Dark Matter, Dark Energy, and MOND from the i-ICST Framework

This work presents a fully revised and numerically tested cosmological model within the Improved Information-Coupled Space-Time (i-ICST) framework. The model adopts a two-field architecture: an information-coupled scalar field C acting as the dark energy component and reproducing MOND-like galactic dynamics, and an ultra-light axion field  serving as cold dark matter (CDM) through the WKB approximation. The study corrects key technical issues from the earlier formulation, including the sign convention of the kinetic variable, the derivation of the kinetic function F (X)  from the MOND interpolation function, and the gravitational-wave speed consistency condition. The revised theory is shown to satisfy the Horndeski gravitational-wave constraint cT² = 1, consistent with current observational bounds. A Chameleon screening mechanism is included to ensure compatibility with Solar System tests, while the cosmological background evolution is solved numerically from z = 10⁵ to z = 0. The model reproduces viable present-day cosmological density fractions and yields falsifiable predictions distinct from CDM, including: - MOND-consistent galactic-scale dynamics - enhanced structure growth f₈ (z)  - suppressed small-scale matter power spectrum - environmental screening signatures - compatibility with Bullet Cluster-type phenomena This deposit contains the full manuscript, including theoretical derivations, perturbation equations, numerical background evolution, observational predictions, and discussion of future tests against cosmological data. Keywords: cosmology, modified gravity, MOND, dark matter, dark energy, axion, scalar field, Horndeski, screening mechanism, i-ICST