Age Estimates of Globular Clusters in the Milky Way: Constraints on Cosmology
Lawrence M. Krauss,1*
Brian Chaboyer2*
Recent observations of stellar globular clusters in the Milky Way
Galaxy, combined with revised ranges of parameters in stellar evolution
codes and new estimates of the earliest epoch of globular cluster
formation, result in a 95% confidence level lower limit on the age of
the Universe of 11.2 billion years. This age is inconsistent with the
expansion age for a flat Universe for the currently allowed range of
the Hubble constant, unless the cosmic equation of state is dominated
by a component that violates the strong energy condition. This means
that the three fundamental observables in cosmology--the age of the
Universe, the distance-redshift relation, and the geometry of the
Universe--now independently support the case for a dark
energy-dominated Universe.
1 Departments of Physics and Astronomy, Case
Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA.
2 Department of Physics and Astronomy,
Dartmouth College, 6127 Wilder Laboratory, Hanover, NH 03755, USA.
*
To whom correspondence should be addressed. E-mail:
lmk9{at}po.cwru.edu, chaboyer{at}heather.dartmouth.edu
