Scalar-tensor-vector gravity theory

A covariant scalar-tensor-vector gravity theory is developed which allows the gravitational constant G, a vector field coupling. and the vector field mass mu to vary with space and time. The equations of motion for a test particle lead to a modified gravitational acceleration law that can fit galaxy rotation curves and cluster data without non-baryonic dark matter. The theory is consistent with solar system observational tests. The linear evolutions of the metric, vector field and scalar field perturbations and their consequences for the observations of the cosmic microwave background are investigated.