Crossing the phantom divide with parametrized post-Friedmann dark energy

By Wenjuan Fang, Wayne Hu, A. Lewis. 2008

184 citations recorded by the source corpus.

Dark energy models with a single scalar field cannot cross the equation of state divide set by a cosmological constant. More general models that allow crossing require additional degrees of freedom to ensure gravitational stability. We show that a parameterized post-Friedmann description of cosmic accelerzation provides a simple but accurate description of multiple scalar field crossing models. Moreover the prescription provides a well-controlled approximation for a wide range of smooth dark energy models. It conserves energy and momentum and is exact in the metric evolution on scales well above and below the transition scale to relative smoothness. Standard linear perturbation tools have been altered to include this description and made publicly available for studies of the dark energy involving cosmological structure out to the horizon scale.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/25f4dd3c2ff8f29043fe3319ce433fa0e5ac0d6c

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Nuclear and High Energy Physics

Citations in the corpus

The clustering of galaxies in the SDSS‐III Baryon Oscillation Spectroscopic Survey: cosmological implications of the large‐scale two‐point correlation function (2012, methodology): “Here we follow the parametrized post-Friedmann (PPF) approach of Fang et al. (2008), as implemented in CAMB, which provides a simple solution to these problems for models in which the dark energy component is smooth compared to the dark matter.”
SEVEN-YEAR WILKINSON MICROWAVE ANISOTROPY PROBE (WMAP) OBSERVATIONS: COSMOLOGICAL INTERPRETATION (2010, methodology): “We use the “parametrized postFriedmann” (PPF) approach, implemented in the CAMB code following Fang et al. (2008).32 In Figure 13, we show the 7-year constraints on w0 and wa from WMAP+H0+SN (red), WMAP+BAO+H0+SN (blue), and WMAP+BAO+H0+D∆t+SN (black).”
Holographic dark energy (2016, methodology): “the gravitational potential and growth of structure. For scalar eld DE models, the uctuation of the scalar eld can be studied using eld theory and is implemented in cosmological codes such as the PPF [263]. Indeed, in the literature the HDE is sometimes modeled by PPF, but as HDE is by nature a cosm”
The Simons Observatory: science goals and forecasts (2018, methodology): “For the dark energy equation of state parameters w0 and wa, we use the Parameterized postFriedmann dark energy model implemented in CAMB (Hu and Sawicki 2007; Hu 2008; Fang et al. 2008b,a).”
SNLS3: CONSTRAINTS ON DARK ENERGY COMBINING THE SUPERNOVA LEGACY SURVEY THREE-YEAR DATA WITH OTHER PROBES (2011, methodology): “For CosmoMC fits where we allow for a time-varying dark energy equation of state (w(a) = w0 + wa(1 − a), where a is the scale factor), we follow the prescription of Fang et al. (2008).”