Derivation of Cosmic Acceleration Given Anisotropic Lightspeed in the Hubble Expansion

The Baryonic Tully-Fisher Relation shows far-field gravitation around spiral galaxies declining as 1/r while Type Ia supernovas point to cosmic acceleration, both phenomena unexplained by general relativity (GR). However, when Einstein's isotropic light-speed is succeeded by more fundamental anisotropic light-speed – specifically, unbounded inward with c/2 outward – within Hubble space-expansion a cosmic time dilation emerges for explaining (pure) cosmic acceleration, a_CA = rH ². Net cosmic acceleration – i.e., pure cosmic acceleration counteracted by (baryonic) GR and subfield cosmic decelerations – is in accord with SNIa luminosity-magnitude (median) residuals in the 0.01 ≤ z ≤ 0.3 redshift range, where the significant complications at greater redshifts are postponed. Uniting cosmic time-dilation with Schwarzschild-solution time dilation allows modeling of 1/r far-field gravitation around galaxies giving a relativistic formulation of Milgrom's Deep MOND. Both advances exhibit the empirical acceleration scale 1.2E-10 m/s^2 and are in accord with Einstein’s gravitational effects near the Sun. Combining subfield gravity and Schwarzschild gravity gives cross-over of the two components at near 7,000 AU from the Sun, in agreement with wide binary star rotation measurements.