Sidney Bludman
Universidad de Chile, Departamento de Astronomía

"Accelerated Cosmological Expansion: Phenomenology"

This phenomenological review stresses the distinction between kinematics, the description of the recently inflationary universe (cosmography), and dynamics, the mechanism driving this accelerating expansion. Because the homogeneous expansion history H(z) of the universe measures only kinematic variables, it cannot fix the underlying dynamics: cosmographic measurements of the homogeneous universe, are consistent with either a static finely-tuned cosmological constant or a dynamic 'dark energy', which itself may be material Dark Energy or modified gravity (Dark Gravity).