Jason Steffen

CHASE Update

Not long ago the Chameleon Afterglow Search (CHASE) reported its results on a search for a candidate dark energy particle. While those results did not report a “chameleon” afterglow signal, it did report an afterglow signal—the “orange glow”. A significant amount of additional data was taken to characterize this orange glow, its color, temperature dependence,… More »

Do we live in a hologram? The number of large spacial dimensions is a question that has periodically resurfaced over the years. Theories derived from black hole thermodynamics state that the area of an event horizon is sufficiently large to hold all of the quantum information of the particles that conspired to make the black… More »


A common explanation for the observed acceleration of the Universe is a scalar field (i.e., scalar particles). However, experiments such as tests of gravity and measurements of fundamental constants place stringent constraints on such particles. At this time there are only three classes of scalar particles that can simultaneously accelerate the Universe and be consistent… More »