David H. Weinberg, Michael J. Mortonson, Daniel J. Eisenstein, Christopher Hirata, Adam G. Riess, Eduardo Rozo
The accelerating expansion of the universe is the most surprising
cosmological discovery in many decades, implying that the universe is dominated
by some form of "dark energy" with exotic physical properties, or that
Einstein's theory of gravity breaks down on cosmological scales. The profound
implications of cosmic acceleration have inspired ambitious experimental
efforts to measure the history of expansion and growth of structure with
percent-level precision or higher. We review in detail the four most well
established methods for making such measurements: Type Ia supernovae, baryon
acoustic oscillations (BAO), weak gravitational lensing, and galaxy clusters.
We pay particular attention to the systematic uncertainties in these techniques
and to strategies for controlling them at the level needed to exploit "Stage
IV" dark energy facilities such as BigBOSS, LSST, Euclid, and WFIRST. We
briefly review a number of other approaches including redshift-space
distortions, the Alcock-Paczynski test, and direct measurements of H_0. We
present extensive forecasts for constraints on the dark energy equation of
state and parameterized deviations from GR, achievable with Stage III and Stage
IV experimental programs that incorporate supernovae, BAO, weak lensing, and
CMB data. We also show the level of precision required for other methods to
provide constraints competitive with those of these fiducial programs. We
emphasize the value of a balanced program that employs several of the most
powerful methods in combination, both to cross-check systematic uncertainties
and to take advantage of complementary information. Surveys to probe cosmic
acceleration produce data sets with broad applications, and they continue the
longstanding astronomical tradition of mapping the universe in ever greater
detail over ever larger scales.
View original:
http://arxiv.org/abs/1201.2434
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