The Nature of Dark Energy - Osmotic Turgor Pressure of the Cosmic Cytosol: A Mechanical Explanation of Time-Dependent Expansion within the Cellular Cosmology Hypothesis

Within the Cellular Cosmology Hypothesis (CCH), the observable universe is modeled as a scalable eukaryotic cell. Dark energy corresponds exactly to the osmotic turgor pressure or the osmotic gradient of the cosmic cytosol — a mechanical, expansive force that stabilizes the “cell volume” against gravitational collapse.This analogy fully resolves the dark energy problem: The accelerated expansion does not arise from a cosmological constant Λ, but from the negative pressure p_DE ≈ −ρ_DE of the osmotic system. The latest DESI DR2 data (2025/2026) show a clear preference for time-dependent w(z) (CPL parametrization: w₀ > −1, wₐ < 0 at 2.8–4.2σ significance in combination with CMB and supernovae). This exact behavior emerges naturally from cosmic senescence: entropy accumulation and degradation of osmotically active components (analogous to telomere shortening, oxidative stress, and reduced ion pump activity in aging cells) lead to a decreasing osmotic activity over time.We derive a modified Friedmann equation incorporating a senescence term, quantify the transition redshift z_tr ≈ 0.5–0.8 as the entry into the senescence phase, and confront the model with DESI BAO, CMB, and SN data. Fifteen new, falsifiable predictions are formulated for JWST, Euclid, LiteBIRD, Roman, and future DESI data releases, including topological aging patterns, correlations with cosmic stress signals, and asymptotic stabilization of the expansion. The CCH thereby unifies dark energy with cellular biological principles and eliminates the need for exotic fields or constants.