Null tests of the cosmological constant using supernovae
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Date
2014
Journal Title
Journal ISSN
Volume Title
Publisher
American Physical Society
Abstract
The standard concordance model of the Universe is based on the cosmological constant as the
driver of accelerating expansion. This concordance model is being subjected to a growing range
of inter-locking observations. In addition to using generic observational tests, one can also design
tests that target the specific properties of the cosmological constant. These null tests do not rely
on parametrizations of observables, but focus on quantities that are constant only if dark energy
is a cosmological constant. We use supernova data in null tests that are based on the luminosity
distance. In order to extract derivatives of the distance in a model-independent way, we use Gaussian
Processes. We find that the concordance model is compatible with the Union 2.1 data, but the error
bars are fairly large. Simulated datasets are generated for the DES supernova survey and we show
that this survey will allow for a sharper null test of the cosmological constant if we assume the
Universe is flat. Allowing for spatial curvature degrades the power of the null test.
Description
Keywords
Gaussian processes, Cosmology, Super nova
Citation
Yahya, S. et al. (2014). Null tests of the cosmological constant using supernovae. Physical Review. D, 89: 023503