Extended Finsler Timescape-Lapse (EFT-Lapse) Theory: Resolving the Hubble Tension by the Geometry of Time

This working paper introduces the Extended Finsler Timescape-Lapse (EFT-Lapse) Theory, a transformative framework that resolves the fundamental cosmological tension between different expansion measurements by treating the expansion rate as a direct consequence of inhomogeneous geometry and bidirectional causality. By anchoring the cosmological coupling to the minimal shear viscosity of the primordial plasma, the model achieves seamless agreement with local astronomical observations without the need for Dark Energy.

As a preliminary theoretical blueprint, this document serves as a foundation for the scientific community to explore and refine a more rigorous, structure-dependent paradigm of spacetime. It is intended to inspire future studies into the geometric origins of cosmic acceleration and the potential for a fully unified, backreaction-based cosmology.

ACKNOWLEDGMENTS AND AI DISCLOSURE

The author acknowledges the use of AI tools (including Perplexity and Google Gemini) for drafting assistance, the derivation and formatting of mathematical equations, computational verification and problem-solving. While these models provided support in refining formulations and verifying solutions, all theoretical conclusions and scientific insights were developed and critically evaluated by the author, who maintains full responsibility for the integrity of the work All theoretical content, ideas, scientific conclusions were developed and critically evaluated by A. Backmund LLM-EFT-Lapse Collaboration. This AI use is disclosed in the spirit of transparency and researcher responsibility as recommended by the European Commission’s “Living Guidelines on the Responsible Use of Generative AI in Research” (2025). The author gratefully acknowledges the provision of foundational datasets by the SH0ES, Planck, and Bayesian QGP collaborations, which were essential for the validation of this working paper