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Probing the nature of dark energy through galaxy redshift surveys with radio telescopes
Author(s) -
Duffy Alan R.
Publication year - 2014
Publication title -
annalen der physik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.009
H-Index - 68
eISSN - 1521-3889
pISSN - 0003-3804
DOI - 10.1002/andp.201400059
Subject(s) - physics , dark energy , radio telescope , redshift , galaxy , astronomy , sky , astrophysics , telescope , universe , radio galaxy , cosmology
Galaxy redshift surveys using optical telescopes have, in combination with other cosmological probes, enabled precision measurements of the nature of dark energy. It is shown that radio telescopes are rapidly becoming competitive with optical facilities in spectroscopic surveys of large numbers of galaxies. Two breakthroughs are driving this change. Firstly, individual radio telescopes are more efficient at mapping the sky thanks to the large field‐of‐view of new phased‐array feeds. Secondly, ever more dishes can be correlated in a cost‐effective manner with rapid increases in computing power. The next decade will see the coming of age of the 21cmradio wavelength as a cosmological probe as first the Pathfinders then, ultimately, the Square Kilometre Array is constructed. The latter will determine precise 3D positions for a billion galaxies, mapping the distribution of matter in the Universe over the last 12 billion years. This radio telescope will be able to constrain the equation of state of dark energy, and its potential evolution, to a precision rivalling that of future optical facilities such as DESI and Euclid.