Rachel Bean, assistant professor of astronomy, has received a 2010 Presidential Early Career Award for Scientists and Engineers (PECASE) for her work in cosmology and theoretical astrophysics.

The award, established in 1996 by President Bill Clinton, is the highest honor bestowed by the U.S. government on outstanding scientists and engineers at the beginning of their careers.

Bean studies cosmological theories and observations to understand the nature of dark energy, the unknown entity thought to be responsible for the accelerated expansion of the universe; and dark matter, matter that appears not to emit or absorb light, and whose existence can only be inferred by its gravitational attraction of other matter. Together, dark matter and dark energy are thought to make up 95 percent of the universe.

She also studies how string theory can be applied toward understanding initial conditions in the early universe.

The award was announced Nov. 9 by the White House Office of Science and Technology Policy.

Ira Wasserman, chair of the Department of Astronomy, praised Bean's work in the search for an explanation behind the universe's accelerating expansion.

"Perhaps the acceleration is due to dark energy; or maybe a failure of general relativity on cosmological distance scales; or even an echo of extra dimensions of space beyond our familiar three," Wasserman said. "Cosmologists are working hard to figure out which of the candidate explanations is true. Rachel is one of the leaders in this campaign."

Bean joined the Cornell faculty in 2005; she was one of five Cornell faculty members to earn an early career award from the National Science Foundation in 2009; and she received a Cottrell Scholar Award from Research Corp. in 2008. Both awards are for early career faculty members who excel at research and teaching.