Fundamental Time Theory in Cosmology: Interpretations and Fit Methodology with Public Data

We introduce the Fundamental Time Theory (FTT), a conceptual framework that interprets time as the fundamental element of the Universe. In this approach, the observed cosmic acceleration is not caused by a mysterious dark energy field but arises naturally from the absence of time beyond the cosmic boundary — the time vacuum. Likewise, dark matter is not attributed to unseen particles but is explained as a geometric effect of local time curvature. Black holes are reinterpreted as temporal rather than spatial singularities. FTT remains consistent with General Relativity (GR) and Quantum Mechanics (QM), reproducing the background evolution of the standard $\Lambda$CDM model while providing an alternative physical interpretation. Observational fits to cosmic chronometers (CC), BOSS DR12 BAO, Pantheon+ supernovae, and Planck 2018 data yield $H_0 = 67.7 \pm 1.0$ km/s/Mpc, $\Omega_{m0} = 0.324 \pm 0.03$, and $q_0 \approx -0.515$, in excellent agreement (94–99%) with standard results. To ensure reproducibility, we provide a supplementary document detailing the fit methodology, datasets, parameters, and statistical procedure. This allows independent verification of the results and invites researchers to test FTT against current and future observations. The intention of this work is not to dismiss existing theories, but to offer a different viewpoint. Even if only a small part proves useful, or if it inspires new ideas that contribute to a better understanding of the Universe, the purpose of this effort will have been achieved.