Model-independent constraints on dark energy and modified gravity with the SKA
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Date
2014
Journal Title
Journal ISSN
Volume Title
Publisher
Proceedings of Science
Abstract
Employing a nonparametric approach of the principal component analysis (PCA), we forecast
the future constraint on the equation of state w(z) of dark energy, and on the effective Newton
constant m(k; z), which parameterise the effect of modified gravity, using the planned SKA HI
galaxy survey. Combining with the simulated data of Planck and Dark Energy Survey (DES), we
find that SKA Phase 1 (SKA1) and SKA Phase 2 (SKA2) can well constrain 3 and 5 eigenmodes
of w(z) respectively. The errors of the best measured modes can be reduced to 0.04 and 0.023
for SKA1 and SKA2 respectively, making it possible to probe dark energy dynamics. On the
other hand, SKA1 and SKA2 can constrain 7 and 20 eigenmodes of m(k; z) respectively within
10% sensitivity level. Furthermore, 2 and 7 modes can be constrained within sub percent level
using SKA1 and SKA2 respectively. This is a significant improvement compared to the combined
datasets without SKA.
Description
Advancing Astrophysics with the Square Kilometre Array
June 8-13, 2014
Giardini Naxos, Italy
Keywords
Principal Component Analysis (PCA), Newton constant, Modified gravity, Dark Energy Survey (DES), Square Kilometre Array (SKA), Cosmic Microwave Background (CMB), Large Scale Structure (LSS)
Citation
Zhao, Gong-Bo, et al., (2014). Model-independent constraints on dark energy and modified gravity with the SKA. Paper presented at Advancing Astrophysics with the Square Kilometre Array, Giardini Naxos, Italy.