What's Inside the Cone? Numerically reconstructing the metric from observations

Abstract

We investigate the possibility of using Gaussian process regression to smooth data on the current past null-cone for use as the input to a relativistic integration scheme. The algorithm we present is designed to reconstruct the metric of spacetime within the class of spherically symmetric dust universes, with or without a cosmological constant. Assuming that gravity is well described by General Relativity, we demonstrate how the algorithm can be employed to test the Copernican principle based on currently available observations. It is shown that currently available data is not sufficient for a conclusive result. The intrinsic noise present in realistic data presents a challenge for our smoothing algorithm and we discuss some of its limitations as well as possible extensions to it. We conclude by demonstrating how a direct determination of the cosmological constant is possible using redshift drift data.

29 pages, 9 figures, published version

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Cited by in corpus (10)

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• Two new tests to the distance duality relation with galaxy clusters
• Geodesic-light-cone coordinates and the Bianchi I spacetime
• Inhomogeneous cosmology and backreaction: Current status and future prospects
• Multi-tasking the growth of cosmological structures
• Characteristic Formulation for Metric $f(R)$ Gravity
• Dodging the dark matter degeneracy while determining the dynamics of dark energy
• Towards the geometry of the universe from data
• Accurate relativistic observables from post-processing light cone catalogues
• From GLC to double-null coordinates and illustration with static black holes