Editor's Summary
31 January 2008
A glimpse of dark energy
Cosmologists can tell from observing distant supernovae that the Universe is undergoing a phase of accelerated expansion, but the physical cause remains a mystery. The favoured explanation requires huge amounts of invisible 'dark energy', distributed across the Universe, forcing expansion via gravitational repulsion. A new survey of redshift distortions of thousands of faint galaxies provides hints as to the nature of dark-energy induced cosmic acceleration. The distortion at a redshift of z = 0.8 is consistent with the standard cosmological-constant model with low matter density and flat geometry. The current error bars are too large to distinguish among alternative origins for the accelerated expansion, but the next generation of galactic surveys, more powerful and far-reaching than the current crop, should provide much tighter constraints on the properties of dark energy.
News and Views: Cosmology: An ancient view of acceleration
The Universe is expanding ever faster — the effect of 'dark energy', most astronomers believe. Surveys of how galaxies were distributed in the past could provide precise clues to what is driving this acceleration.
Michael A. Strauss
doi:10.1038/451531a
Letter: A test of the nature of cosmic acceleration using galaxy redshift distortions
L. Guzzo, M. Pierleoni, B. Meneux, E. Branchini, O. Le Fèvre, C. Marinoni, B. Garilli, J. Blaizot, G. De Lucia, A. Pollo, H. J. McCracken, D. Bottini, V. Le Brun, D. Maccagni, J. P. Picat, R. Scaramella, M. Scodeggio, L. Tresse, G. Vettolani, A. Zanichelli, C. Adami, S. Arnouts, S. Bardelli, M. Bolzonella, A. Bongiorno, A. Cappi, S. Charlot, P. Ciliegi, T. Contini, O. Cucciati, S. de la Torre, K. Dolag, S. Foucaud, P. Franzetti, I. Gavignaud, O. Ilbert, A. Iovino, F. Lamareille, B. Marano, A. Mazure, P. Memeo, R. Merighi, L. Moscardini, S. Paltani, R. Pellò, E. Perez-Montero, L. Pozzetti, M. Radovich, D. Vergani, G. Zamorani & E. Zucca
doi:10.1038/nature06555
First paragraph | Full Text | PDF (423K) | Supplementary information
