Optimizing future imaging survey of galaxies to confront dark energy and modified gravity models

Abstract

We consider the extent to which future imaging surveys of galaxies can distinguish between dark energy and modified gravity models for the origin of the cosmic acceleration. Dynamical dark energy models may have similar expansion rates as models of modified gravity, yet predict different growth of structure histories. We parameterize the cosmic expansion by the two parameters, $w_0$ and $w_a$, and the linear growth rate of density fluctuations by Linder's $\gamma$, independently. Dark energy models generically predict $\gamma \approx 0.55$, while the DGP model $\gamma \approx 0.68$. To determine if future imaging surveys can constrain $\gamma$ within 20 percent (or $\Delta \gamma <0.1$), we perform the Fisher matrix analysis for a weak lensing survey such as the on-going Hyper Suprime-Cam (HSC) project. Under the condition that the total observation time is fixed, we compute the Figure of Merit (FoM) as a function of the exposure time $\texp$. We find that the tomography technique effectively improves the FoM, which has a broad peak around $\texp\simeq {\rm several}\sim 10$ minutes; a shallow and wide survey is preferred to constrain the $\gamma$ parameter. While $\Delta \gamma <0.1$ cannot be achieved by the HSC weak-lensing survey alone, one can improve the constraints by combining with a follow-up spectroscopic survey like WFMOS and/or future CMB observations.

18 pages, typos corrected

References in corpus (9)

• Accurate photometric redshifts for the CFHT Legacy Survey calibrated using the VIMOS VLT Deep Survey
• Dark Energy versus Modified Gravity
• Separating Dark Physics from Physical Darkness: Minimalist Modified Gravity vs. Dark Energy
• Observational constraints on self-accelerating cosmology
• Large-Scale Tests of the DGP Model
• Non-linear interactions in a cosmological background in the DGP braneworld
• Optimising Baryon Acoustic Oscillation Surveys - I: Testing the concordance LCDM cosmology
• Searching for modified gravity with baryon oscillations: from SDSS to wide field multiobject spectroscopy (WFMOS)
• Color Tomography

Cited by in corpus (21)

• Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• f(R) theories
• Modified gravity models of dark energy
• Non-linear Evolution of Matter Power Spectrum in Modified Theory of Gravity
• The dispersion of growth of matter perturbations in f(R) gravity
• Evolution of linear cosmological perturbations and its observational implications in Galileon-type modified gravity
• Large Scale Structures in Kinetic Gravity Braiding Model That Can Be Unbraided
• Parameterizing the Effect of Dark Energy Perturbations on the Growth of Structures
• Impact of the non-Gaussian covariance of the weak lensing power spectrum and bispectrum on cosmological parameter estimation
• Constraint on the cosmological f(R) model from the multipole power spectrum of the SDSS luminous red galaxy sample and prospects for a future redshift survey
• Weak lensing predictions for modified gravities at non-linear scales
• Probing dark energy and neutrino mass from upcoming lensing experiments of CMB and galaxies
• Characterizing the linear growth rate of cosmological density perturbations in an f(R) model
• Magnification effect on the detection of primordial non-Gaussianity from photometric surveys
• Weak lensing induced by second-order vector mode
• Optimizing baryon acoustic oscillation surveys II: curvature, redshifts, and external datasets
• Damping of the baryon acoustic oscillations in the matter power spectrum as a probe of the growth factor
• Constraints on primordial non-Gaussianity from Galaxy-CMB lensing cross-correlation
• The Distinguishability of Interacting Dark Energy from Modified Gravity
• Optimising Spectroscopic and Photometric Galaxy Surveys: Efficient Target Selection and Survey Strategy