2011/11/30 by Alireza Hojjati, Gong‐Bo Zhao, Gong-Bo Zhao +5 · 87 citations
Mathematics · Physics and Astronomy · #Astrophysics #Classical mechanics #Cosmology #Cosmology and Gravitation Theories #Curvature #Dark energy #Degeneracy (biology) #Eigenvalues and eigenvectors #Galaxies: Formation, Evolution, Phenomena #Galaxy #Gamma-ray bursts and supernovae #General relativity #Geometry #Gravitation #Mathematics #Physics #Principal component analysis #Quantum mechanics #Redshift #Statistical physics #Statistics #Theoretical physics #Weak gravitational lensing #astro-ph.CO #gr-qc
paper · pdf · doi:10.1103/physrevd.85.043508
published in Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields 85(4) (American Physical Society) · 18 pages, 24 figures
openalex publication_date 2012/02/07 · arxiv created 2012/02/10 · arxiv updated 2012/02/14 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The next generation of weak lensing surveys will trace the evolution of matter perturbations and gravitational potentials from the matter dominated epoch until today. Along with constraining the dynamics of dark energy, they will probe the relations between matter overdensities, local curvature, and the Newtonian potential. We work with two functions of time and scale to account for any modifications of these relations in the linear regime from those in the \ensuremathΛCDM model. We perform a principal component analysis (PCA) to find the eigenmodes and eigenvalues of these functions for surveys like the Dark Energy Survey and Large Synoptic Survey Telescope. This paper builds on and significantly extends the PCA analysis of Zhao et al. [Phys. Rev. Lett. 103, 241301 (2009)] in several ways. In particular, we consider the impact of some of the systematic effects expected in weak lensing surveys. We also present the PCA in terms of other choices of the two functions needed to parametrize modified growth on linear scales, and discuss their merits. We analyze the degeneracy between the modified growth functions and other cosmological parameters, paying special attention to the effective equation of state w(z). Finally, we demonstrate the utility of the PCA as an efficient data compression stage which enables one to easily derive constraints on parameters of specific models without recalculating Fisher matrices from scratch.