The term “dark energy” was coined as recently as 1999, yet it has become one of the most mysterious and frequently debated topics in physics. Millions of pounds and countless hours are being spent on imaging and spectrographic surveys that aim to explain why observations point to the accelerating expansion of the universe – and with good reason. It has become apparent that the Earth, the planet...

We investigate the value of future dark-energy experiments by modeling their ability to constrain the darkenergy equation of state. Similar work was recently reported by the Dark Energy Task Force (DETF) using a two dimensional parameterization of the equation-of-state evolution. We examine constraints in a ninedimensional dark-energy parameterization, and find that the best experiments constra...

Several models have been proposed to explain the dark energy that is causing universe expansion to accelerate. Here the acceleration predicted by the Holographic Dark Information Energy (HDIE) model is compared to the acceleration that would be produced by a cosmological constant. While identical to a cosmological constant at low redshifts, z < 1, the HDIE model results in smaller Hubble parame...