How real-time cosmology can distinguish between different anisotropic models

Abstract

We present a new analysis on how to distinguish between isotropic and anisotropic cosmological models based on tracking the angular displacements of a large number of distant quasars over an extended period of time, and then performing a multipole-vector decomposition of the resulting displacement maps. We find that while the GAIA mission operating at its nominal specifications does not have sufficient angular resolution to resolve anisotropic universes from isotropic ones using this method within a reasonable timespan of ten years, a next-generation GAIA-like survey with a resolution ten times better should be equal to the task. Distinguishing between different anisotropic models is however more demanding. Keeping the observational timespan to ten years, we find that the angular resolution of the survey will need to be of order 0.1 micro-arcsecond in order for certain rotating anisotropic models to produce a detectable signature that is also unique to models of this class. However, should such a detection become possible, it would immediately allow us to rule out large local void models.

25 pages, 4 figures; v2: 27 pages, 5 figures in new colour scheme, extended discussion on the uniqueness of the observer position, main conclusions unchanged, matches version accepted by JCAP

References in corpus (13)

• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Data Processing, Sky Maps, and Basic Results
• Testing the Void against Cosmological data: fitting CMB, BAO, SN and H0
• Real-time Cosmology
• Observational constraints on the LLTB model
• Cosmic Parallax: possibility of detecting anisotropic expansion of the universe by very accurate astrometry measurements
• Perceiving the equation of state of Dark Energy while living in a Cold Spot
• Can cosmological perturbations produce early universe vorticity?
• Cosmic Parallax as a probe of late time anisotropic expansion
• Cosmic Parallax in Ellipsoidal Universe
• Corrections to the apparent value of the cosmological constant due to local inhomogeneities
• Effects of voids on the reconstruction of the equation of state of Dark Energy
• Testing the statistical isotropy of large scale structure with multipole vectors
• Cosmology when living near the Great Attractor

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• The Gaia-WISE Extragalactic Astrometric Catalog
• The Hubble Expansion is Isotropic in the Epoch of Dark Energy
• Cosmography and the redshift drift in Palatini $f(\mathcal{R})$ theories
• Algebraic symmetries of the observables on the sky: Variable emitters and observers