Author(s)

Egbertus Paulus Johannes de Haas

Kandinsky College, Nijmegen, Netherlands.

We investigate the influence of the Hubble parameter $H\left(z\right)$ on galactic dynamics and morphology. By introducing the cosmic expansion as an effective limit on Newtonian gravitation, we obtain a redshift-dependent critical radius that constrains both spiral structure and rotation curves. Galactic bars are interpreted as frozen spirals of high-$z$ epochs nested inside extended low-$z$ spirals. This framework naturally explains the coexistence of bulges, bars, disks and halos as the outcome of metric inflow and bulge reset events. The resulting morphology and kinematics provide a direct and testable connection between galactic structure and the cosmic expansion. We argue that this approach opens a new possibility to empirically derive $H\left(z\right)$ from galaxy morphology and rotation curves and allows reconstructing the expansion history of the universe on galactic scales.

Alternative Gravity Theory, Quantum Gravity, Space Quantisation, Dark Matter, Dark Energy, Hubble Expansion

de Haas, E.P.J. (2025) The Role of the Hubble Parameter in Galactic Rotation Curves and Spiral Morphology. Journal of High Energy Physics, Gravitation and Cosmology, 11, 1595-1612. doi: 10.4236/jhepgc.2025.114097.