NASA Funds Investigation of a Cosmic Mystery
UT Dallas Team to Study Gravity's Failure to Slow the Expansion of the Universe
Feb. 19, 2010
Cosmologist Dr. Mustapha Ishak-Boushaki received a $180,000 NASA grant to embark on a two-year study of new models to explain why our universe is picking up speed while it tears itself apart.
Ishak-Boushaki, an assistant professor of physics and principal investigator of the UT Dallas Astrophysics, Cosmology and Relativity Group, is using mathematical and numerical tools to explore cosmological models, called Szekeres models, which may offer a more complete explanation of cosmic acceleration than previous models.
Cosmology is the branch of astrophysics concerned with the origin, evolution and structure of the universe. Widely considered the most perplexing problem to ever confront astrophysicists, the universe presents a baffling contradiction to logic: gravity should slow the expansion of the universe, not let it speed up.
“One of the pressing questions in cosmology is to find the physical cause of cosmic acceleration,” Ishak-Boushaki said. “Cosmic acceleration can be caused by a repulsive dark energy in the universe, or it can be caused by some changes to gravity physics at very large, cosmological scales. A third possibility, one we’re also exploring, is simply that cosmic acceleration may just be an apparent effect. In other words, we’re attempting to see if it’s really happening at all.”
According to Ishak-Boushaki, measurements of light from supernovae are used to determine the speed and rate of expansion of the universe. But at extraordinarily large, cosmic scales, there’s a possibility that irregularities in the universe over vast distances can distort observations and suggest the universe is accelerating, when in fact it isn’t.
“This can be the result of an uneven rate of expansion from one region of the universe to another,” Ishak-Boushaki said.
Ishak-Boushaki and fellow Cosmologist Dr. Wolfgang Rindler team with eight graduate students to form the cosmology group. Their studies include cosmic acceleration, dark energy, gravitational lensing (when light from a distance source is “bent” around huge objects, like clusters of galaxies) and other aspects of cosmology.
“The cosmology group is booming with projects,” Ishak-Boushaki said. “The funding from NASA is already generating some promising preliminary results.”
Dr. Mustapha Ishak-Boushaki is leading a team confronting the most perplexing problem to confront astophysicists.
The UT Dallas Astrophysics, Cosmology and Relativity Group is exploring models that may offer a more complete explanation of cosmic acceleration than previous models.