A single parameterization for dark energy and modified gravity models

Abstract

Perhaps the most explored hypothesis for the accelerated cosmic expansion rate arises in the context of extra fields or modifications to General Relativity. A prevalent approach is to parameterize the expansion history through the equation of state, $\omega (z)$. We present a parametric form for $\omega (z)$ that can reproduce the generic behavior of the most widely used physical models for accelerated expansion with infrared corrections. The present proposal has at most 3 free parameters which can be mapped back to specific archetypal models for dark energy. We analyze in detail how different combinations of data can constrain the specific cases embedded in our form for $\omega (z)$. We implement our parametric equation for $\omega (z)$ to observations from CMB, the luminous distance of SNeIa, cosmic chronometers, and baryon acoustic oscillations identified in galaxies and in the Lymann-$\alpha$ forest. We find that the parameters can be well constrained by using different observational data sets. Our findings point to an oscillatory behavior consistent with an $f(R)$-like model or an unknown combination of scalar fields. When we let the three parameters vary freely, we find an EoS which oscillates around the phantom-dividing line, and, with over 99$\%$ of confidence, the cosmological constant solution is disfavored.

18 figures, two tables, 22 pages. Accepted version for publication in Physics of the Dark Universe. One section and one appendix were added

References in corpus (15)

• Dark energy cosmology: the equivalent description via different theoretical models and cosmography tests
• In the Realm of the Hubble tension $-$ a Review of Solutions
• Large Magellanic Cloud Cepheid Standards Provide a 1% Foundation for the Determination of the Hubble Constant and Stronger Evidence for Physics Beyond LambdaCDM
• The Clustering of the SDSS DR7 Main Galaxy Sample I: A 4 per cent Distance Measure at z=0.15
• Improved Cosmological Constraints from New, Old and Combined Supernova Datasets
• Spectra and Light Curves of Six Type Ia Supernovae at 0.511 < z < 1.12 and the Union2 Compilation
• The DESI Experiment Part I: Science,Targeting, and Survey Design
• Improved Dark Energy Constraints from ~100 New CfA Supernova Type Ia Light Curves
• Baryon Acoustic Oscillations in the Lyα forest of BOSS DR11 quasars
• The DESI Experiment Part II: Instrument Design
• The 2dF Galaxy Redshift Survey: Final Data Release
• Can dark energy be dynamical?
• Planck priors for dark energy surveys
• Probing a Steep EoS for Dark Energy with latest observations
• Isogrowth Cosmology (and How to Map the Universe)

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• Emulating dark energy models with known equation of state via the created cold dark matter scenario
• Revisiting CPL with sign-switching density: To cross or not to cross the NECB
• Dynamics of pairwise motions in the fully non-linear regime in LCDM and Modified Gravity cosmologies
• Cluster gravitational redshifts: uncertainties and survey requirements
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