Evidence for Galaxy Dynamics Tracing Background Cosmology Below the de Sitter Scale of Acceleration

Galaxy dynamics probe weak gravity at accelerations below the de Sitter scale of acceleration $a_{dS}=cH$, where c is the velocity of light and H is the Hubble parameter. Low- and high-redshift galaxies hereby offer a novel probe of weak gravity in an evolving cosmology, satisfying $H\left(z\right)=H_0\sqrt{1+{\omega }_m(6z+12z^2+12z^3+6z^4+(6/5\left)z^5\right)}$/$(1+z)$ with matter content ${\omega }_m=0.2808\pm 0.028$ sans tension to H ₀ in surveys of the local universe. Galaxy rotation curves show anomalous galaxy dynamics in weak gravity $a_N<a_{dS}$ across a transition radius $r_t=4.7kpc{M}_{11}^{1/2}{\left(H_0/H\right)}^{\frac{1}{2}}$ in galaxies of mass $M={10}^{11}{M}_{\odot }{M}_{11}$, where a _N is the Newtonian acceleration based on baryonic matter content. We identify this behavior with a holographic origin of inertia from entanglement entropy, which introduces a C ⁰ onset across $a_N=a_{dS}$ with asymptotic behavior described by a Milgrom parameter satisfying $a_0={\omega }_0/2\pi$, where ${\omega }_0=\sqrt{1-q}H$ is a fundamental eigenfrequency of the cosmological horizon. Extending an earlier confrontation with data covering $0.003\lesssim a_N/a_{dS}\lesssim 1$ at redshift $z\sim 0$ in Lellie et al., the modest anomalous behavior in the Genzel et al. sample at redshifts $0.854⩽z⩽2.282$ is found to be mostly due to clustering $0.36\lesssim a_N/a_{dS}\lesssim 1$ close to the C ⁰ onset to weak gravity and an increase of up to 65% in a ₀.