All Outputs (7)

Cosmological perturbations in generalised dark Lagrangians (2018)
Journal Article
Edholm, J., & Pearson, J. (2018). Cosmological perturbations in generalised dark Lagrangians. Journal of High Energy Physics, 2018(11), Article 180. https://doi.org/10.1007/jhep11%282018%29180

We describe a new method to parameterise dark energy theories including massive gravity, elastic dark energy and tensor-metric theories. We first examine the existing framework which describes any second order Lagrangian which depends on the variatio... Read More about Cosmological perturbations in generalised dark Lagrangians.

Constraining dark sector perturbations 1: cosmic shear and CMB lensing (2015)
Journal Article
Battye, R. A., Moss, A., & Pearson, J. A. (2015). Constraining dark sector perturbations 1: cosmic shear and CMB lensing. Journal of Cosmology and Astroparticle Physics, 2015, Article 048. https://doi.org/10.1088/1475-7516/2015/04/048

We present current and future constraints on equations of state for dark sector perturbations. The equations of state considered are those corresponding to a generalized scalar field model and time-diffeomorphism invariant Script L(g) theories that a... Read More about Constraining dark sector perturbations 1: cosmic shear and CMB lensing.

Material models of dark energy (2014)
Journal Article
Pearson, J. A. (2014). Material models of dark energy. Annalen der Physik, 526(7-8), 318-339. https://doi.org/10.1002/andp.201400052

A new class of “dark energy” models is reviewed and developed, in which the relativistic theory of solids is used to construct material models of dark energy. These are models which include the effects of a continuous medium with well defined physica... Read More about Material models of dark energy.

Simple implementation of general dark energy models (2014)
Journal Article
Bloomfield, J. K., & Pearson, J. A. (2014). Simple implementation of general dark energy models. Journal of Cosmology and Astroparticle Physics, 2014, Article 17. https://doi.org/10.1088/1475-7516/2014/03/017

We present a formalism for the numerical implementation of general theories of dark energy, combining the computational simplicity of the equation of state for perturbations approach with the generality of the effective field theory approach. An effe... Read More about Simple implementation of general dark energy models.

Computing model independent perturbations in dark energy and modified gravity (2014)
Journal Article
Battye, R. A., & Pearson, J. A. (2014). Computing model independent perturbations in dark energy and modified gravity. Journal of Cosmology and Astroparticle Physics, 2014(03), Article 051. https://doi.org/10.1088/1475-7516/2014/03/051

We present a methodology for computing model independent perturbations in dark energy and modified gravity. This is done from the Lagrangian for perturbations, by showing how field content, symmetries, and physical principles are often sufficient ing... Read More about Computing model independent perturbations in dark energy and modified gravity.

Massive gravity, the elasticity of space-time, and perturbations in the dark sector (2013)
Journal Article
Battye, R., & Pearson, J. (2013). Massive gravity, the elasticity of space-time, and perturbations in the dark sector. Physical Review D, 88(8), Article 084004. https://doi.org/10.1103/physrevd.88.084004

We consider a class of phenomenological modified gravity models where the terms added to the standard Einstein-Hilbert Lagrangian are just a function of the metric only. For linearized perturbations around an isotropic space-time, this class of model... Read More about Massive gravity, the elasticity of space-time, and perturbations in the dark sector.

Parametrizing dark sector perturbations via equations of state (2013)
Journal Article
Battye, R. A., & Pearson, J. A. (2013). Parametrizing dark sector perturbations via equations of state. Physical Review D, 88(6), Article 061301. https://doi.org/10.1103/physrevd.88.061301

The evolution of perturbations is a crucial part of the phenomenology of the dark sector cosmology. We advocate parametrizing these perturbations using equations of state for the entropy perturbation and the anisotropic stress. For small perturbation... Read More about Parametrizing dark sector perturbations via equations of state.