Designing a space-based galaxy redshift survey to probe dark energy
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Author
Wang, Yun
Percival, Will
Cimatti, Andrea
Mukherjee, Pia
Guzzo, Luigi
Baugh, Carlton M.
Carbone, Carmelita
Franzetti, Paolo
Garilli, Bianca
Geach, James E.
Lacey, Cedric G.
Majerotto, Elisabetta
Orsi, Alvaro
Rosati, Piero
Samushia, Lado
Zamorani, Giovanni
Attention
2299/11311
Abstract
A space-based galaxy redshift survey would have enormous power in constraining dark energy and testing general relativity, provided that its parameters are suitably optimized. We study viable space-based galaxy redshift surveys, exploring the dependence of the Dark Energy Task Force (DETF) figure-of-merit (FoM) on redshift accuracy, redshift range, survey area, target selection and forecast method. Fitting formulae are provided for convenience. We also consider the dependence on the information used: the full galaxy power spectrum P(k), P(k) marginalized over its shape, or just the Baryon Acoustic Oscillations (BAO). We find that the inclusion of growth rate information (extracted using redshift space distortion and galaxy clustering amplitude measurements) leads to a factor of similar to 3 improvement in the FoM, assuming general relativity is not modified. This inclusion partially compensates for the loss of information when only the BAO are used to give geometrical constraints, rather than using the full P(k) as a standard ruler. We find that a space-based galaxy redshift survey covering similar to 20 000 deg(2) over 0.5 less than or similar to z less than or similar to 2 with sigma(z)/(1 + z)