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Title: Exploring scalar field dynamics with Gaussian processes

The origin of the accelerated expansion of the Universe remains an unsolved mystery in Cosmology. In this work we consider a spatially flat Friedmann-Robertson-Walker (FRW) Universe with non-relativistic matter and a single scalar field contributing to the energy density of the Universe. Properties of this scalar field, like potential, kinetic energy, equation of state etc. are reconstructed from Supernovae and BAO data using Gaussian processes. We also reconstruct energy conditions and kinematic variables of expansion, such as the jerk and the slow roll parameter. We find that the reconstructed scalar field variables and the kinematic quantities are consistent with a flat ΛCDM Universe. Further, we find that the null energy condition is satisfied for the redshift range of the Supernovae data considered in the paper, but the strong energy condition is violated.
Authors:
;  [1] ;  [2]
  1. Centre for Theoretical Physics, Jamia Millia Islamia, New Delhi 110025 (India)
  2. Deen Dayal Upadhyaya College, University of Delhi, New Delhi 110015 (India)
Publication Date:
OSTI Identifier:
22369835
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2014; Journal Issue: 01; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COSMOLOGY; ENERGY DENSITY; EQUATIONS OF STATE; EXPANSION; GAUSSIAN PROCESSES; KINETIC ENERGY; MATTER; ORIGIN; RED SHIFT; RELATIVISTIC RANGE; SCALAR FIELDS; SUPERNOVAE; UNIVERSE