The UD Origin of Gravitational Waves: The Pull of D on U and the Ripples of Spacetime

This paper demonstrates that gravitational waves are the propagation of the pull of D (matter) on U (space) in wave form. From the UD action, the linearized Einstein equation is derived from first principles. Since the energy-momentum tensor includes both visible matter and dark matter (UD), dark matter necessarily generates gravitational waves—a logical consequence of UD theory. The wave speed and tensor polarizations are identical to GR, consistent with LIGO observations. The geometric postulate of GR is replaced by a physical mechanism: the U-D interaction.