Detailed Analysis of the Probability of a Sharp Increase in the Universe's Expansion Rate Due to the Spread of Life in the Universe in the Context of the Acta Universi Hypothesis

The hypothesis of Acta Universi (AU-field), proposed in 2025, reinterprets dark energy as a universal archive of events, where entropy S_Θ, generated by life processes, directly influences the cosmological constant Λ_eff and the expansion rate H(t). This article analyzes the probability of a sharp increase in the universe's expansion rate—potentially leading to a phantom energy regime (w < -1) and a Big Rip scenario—as a consequence of the cosmic spread of life through panspermia or technological colonization. In standard cosmology, this probability is low (~1–5%), as life's entropy production is negligible on cosmic scales. In Acta Universi, it is high (50–90%), as life's exponential spread boosts S_total,…