Testing the Zero Dark Energy Hypothesis:A Numerical Simulation of Friedmann Cosmology Beyond LCDM

Abstract

This study investigates the cosmological consequences of eliminating or drastically reducing the dark energy density parameter (Ωλ) from the standard ΛCDM model. Using a numerical integration of the Friedmann equations, we simulate the temporal evolution of the scale factor a(t), the Hubble parameter H(z), and the deceleration parameter q(z) across three model classes: the standard ΛCDM benchmark (Ωλ = 0.685), a no-dark-energy model (Ωλ = 0), and an ensemble of six randomised low-Λ universes with Ωλ ∈ [0, 0.25]. The simulation introduces a “solidification” visualisation of fractional energy density evolution, revealing how each cosmic component (radiation, matter, curvature, and dark energy) dominated the universe’s energy budget across its history. Results confirm that the removal of dark energy eliminates the late-time acceleration transition observed at z ≈ 0.6–0.7 in ΛCDM, produces a permanently positive deceleration parameter, and yields a universe age substantially deviating from the observed ~13.8 Gyr. The implications for cosmological model selection, the fine-tuning problem, and observational falsifiability are discussed.