From Stellar Death to Cosmic Rebirth: A Cosmological Framework within Fundamental Speed Theory

We develop a cosmological framework derived from the five foundational equations of the Fundamental Speed Theory (FST) (1). The manuscript links three topics commonly treated separately: (i) the interpretation of compact objects in FST, (ii) the background expansion history, and (iii) long-timescale evolution in a cyclic scenario. Part I - Theoretical foundations: We define three dynamical states — Ordinary, Raw, and Critical — distinguished by the relative velocity dispersion between constituents. In the interpretation adopted here, stellar collapse provides a pathway to the Raw-state regime. The small-radius behavior summarized in Appendix F is used to motivate an effective mechanism that can halt collapse prior to a curvature singularity, so that black holes are treated as reservoirs of a low-collision (effectively non-interacting) phase. The framework further considers hierarchical mergers that consolidate matter into a single Grand Object, characterized (within this model) by representative scales G_{\mathrm{eff}}^{\mathrm{(GO)}}\approx 10^{24}G_{0} and R_{\mathrm{GO}}\approx 10^{50}\mathrm{m}. Part II - Cosmological dynamics: We derive a background expansion law from the evolution of G_{\mathrm{eff}} and examine the use of standard linear-growth benchmarks in the absence of particle dark matter in FST. Appendix G states a self-consistency condition in the linear, large-scale regime: an effective-gravity source accounting (including a Raw-sector contribution) can reproduce the benchmark growth history at the precision level of the tests employed. The parameter \alpha controls the logarithmic evolution of G_{\mathrm{eff}}(z). Part III - Observational comparison: Using a joint analysis of Cosmic Chronometers, Type Ia Supernovae, Baryon Acoustic Oscillations, and the Planck 2018 compressed CMB likelihood,