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Reconstruction of general scalar-field dark energy models

Shinji Tsujikawa
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Abstract

The reconstruction of scalar-field dark energy models is studied for a general Lagrangian density $p(ϕ, X)$, where $X$ is a kinematic term of a scalar field $ϕ$. We implement the coupling $Q$ between dark energy and dark matter and express reconstruction equations using two observables: the Hubble parameter $H$ and the matter density perturbation $δ_m$. This allows us to determine the structure of corresponding theoretical Lagrangian together with the coupling $Q$ from observations. We apply our formula to several forms of Lagrangian and present concrete examples of reconstruction by using the recent Gold dataset of supernovae measurements. This analysis includes a generalized ghost condensate model as a way to cross a cosmological-constant boundary even for a single-field case.

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Shinji Tsujikawa. 2005-10-19. Reconstruction of general scalar-field dark energy models. https://doi.org/10.1103/physrevd.72.083512

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