Spiral Galaxies as Self-Lensing Relativistic Onions: Dual Precession in Rotating Axisymmetric Metrics, and Its Implications for Galactic Dynamics and Local Cosmology (exploratory)

The Relativistic Onion: Dual Precession in Rotating Axisymmetric Metrics and Its Implications for Galactic Dynamics and Local Cosmology

We explore a speculative extension of the Papapetrou metric to thick, differentially rotating galactic disks, dubbed the "Relativistic Onion" model. This framework incorporates dual precession (g_{tϕ} and g_{rθ}) and time-dependent geodesic integration. Also, by integrating the median gravitational potential (rather than the mean) and accounting for the rotation of the potential over ∼10⁵-year photon travel times, the model quantitatively reproduces observed flat rotation curves, approaching/receding asymmetries, warps, flaring, and excess vertical dispersion without invoking dark matter.

Preliminary comparisons to NGC 3198 and the Milky Way suggest qualitative agreement with observations without the nned for dark matter, though rigorous validation through numerical simulations and extended data fits is required.

The model also predicts a local bias in low-redshift H₀ measurements due to relativistic self-lensing of the Milky Way, potentially contributing to the Hubble tension.

The author, a hospital anaesthetist with no formal astrophysics training, developed these ideas through personal reflection and used a large language model solely as a tool for structuring and stress-testing the concepts. This work is offered as an exploratory, conceptual note inviting collaboraiton and rigorous numerical validation by the astrophysics community.

Keywords : General relativity, galactic rotation curves, dark matter alternatives, frame-dragging, Hubble tension, self-lensing.