Effective Field Theory of Cosmic Acceleration: an implementation in CAMB

By Bin Hu, M. Raveri, N. Frusciante, A. Silvestri. 2013

169 citations recorded by the source corpus.

We implement the effective field theory (EFT) approach to dark energy and modified gravity in the public Einstein-Boltzmann solver CAMB. The resulting code, which we dub EFTCAMB, is a powerful and versatile tool that can be used for several objectives. It can be employed to evolve the full dynamics of linear scalar perturbations in any given single field dark energy or modified gravity model, once the latter is mapped into the EFT formalism. It offers a numerical implementation of EFT as a model-independent framework to test gravity on cosmological scales. EFTCAMB has a built-in check for the fulfillment of general stability conditions such as the absence of ghost and superluminal propagation of perturbations. It handles phantom-divide crossing models and does not contain any quasi-static approximation, but rather evolves the full dynamics of perturbations on linear scales. As we will show, the latter is an important feature in view of the accuracy and scale range of upcoming surveys. We show the reliability and applicability of our code by evolving the dynamics of linear perturbations and extracting predictions for power spectra in several models. In particular we perform a thorough analysis of f(R) theories, comparing our outputs with those of an existing code for LCDM backgrounds, and finding an agreement that can reach 0.1% for models with a Compton wavelength consistent with current cosmological data. We then showcase the flexibility of our code studying two different scenarios. First we produce new results for designer f(R) models with a time-varying dark energy equation of state. Second, we extract predictions for linear observables in some parametrized EFT models with a phantom-divide crossing equation of state for dark energy.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/76c61bd1333572068bb8f27eef15f1e593585b77

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Citations in the corpus

Beyond the Cosmological Standard Model (2014, unknown): “On a practical note, the public Boltzman–Einstein solver CAMB has been upgraded by [991] to include MG predictions using an effective field theory approach (see also [913]).”
A unifying description of dark energy (2014, methodology): “These equations can be solved in a modified Boltzmann code; for instance, they have been recently implemented in a code in [45, 46].”
Cosmological tests of modified gravity (2015, methodology): “These equations have been implemented to the linear Einstein-Boltzmann code [254, 255, 256].”
Effective field theory of dark energy: A review (2019, methodology): “Different time behaviors for the EFT functions {Ω, γ1, γ2} of the EFTCAMB basis have been explored further by considering also the constraints on GWs which suggest γ3 = 0 [130].”
Maximal freedom at minimum cost: linear large-scale structure in general modifications of gravity (2014, unknown): “[41] in the effective field theory formalism.”
hi_class: Horndeski in the Cosmic Linear Anisotropy Solving System (2016, background): “• EFTCAMB [83, 84], a publicly available implementation of the EFT of dark energy.”
Cosmology and Fundamental Physics with the Euclid Satellite (2012, methodology): “This method is now employed in the publicly available Boltzmann codes EFTCAMB (Hu et al. 2014), used also in the planck analysis on dark energy and modified gravity (Planck Collaboration 2016c), and hi_class (Zumalacárregui et al.”
Dark Energy in Light of Multi-Messenger Gravitational-Wave Astronomy (2018, unknown): “Publicly available implementations exist in EFTCAMB [185], hi class [186] and COOP [187], with the first two based on the CAMB and CLASS Boltzmann codes [188, 189].”