Low-redshift BAO without dark components: testing the TCR-Cosmo model

This preprint presents TCR-Cosmo, a cosmological model deposited to establish priority and guarantee open access. Built upon the relational and pre-spatiotemporal ontology of the Teoria della Coesistenza Relazionale (TCR), TCR-Cosmo departs from the standard ΛCDM paradigm by not requiring dark components to explain late-time cosmic acceleration. Instead, the observed dynamics emerge from the relational lapse and the growth of cosmic voids, moderated by collapsed structures such as galaxies and black holes. Using the same official datasets employed in ΛCDM analyses, cosmic chronometers (CC), type Ia supernovae (SN), and baryon acoustic oscillations (BAO), the model is quantitatively tested at low redshift. Results show that TCR-Cosmo achieves a global fit comparable to ΛCDM and performs slightly better for low-redshift BAO measurements. In the TCR-Cosmo perspective, cosmic acceleration is not the signal of hypothetical dark components, but the macroscopic manifestation of relational variations. The model is presented as an open research program: it provides a falsifiable framework, preliminary predictions for precision cosmology, and a transparent methodology designed for reproducibility.