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Dark Energy Survey year 1 results: Constraints on extended cosmological models from galaxy clustering and weak lensing

Publications associées (102)

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On the effect of image denoising on galaxy shape measurements

Frédéric Courbin, Georges Meylan, Marc Gentile, Guldariya Nurbaeva

Weak gravitational lensing is a very sensitive way of measuring cosmological parameters, including dark energy, and of testing current theories of gravitation. In practice, this requires exquisite measurement of the shapes of billions of galaxies over larg ...

2011

Scale-invariant alternatives to general relativity

Diego Blas Temino

We study the general class of gravitational field theories constructed on the basis of scale invariance (and therefore absence of any mass parameters) and invariance under transverse diffeomorphisms, which are the 4-volume conserving coordinate transformat ...

2011

Non-linear matter power spectrum from Time Renormalisation Group: efficient computation and comparison with one-loop

Julien Lesgourgues, Benjamin Audren

We address the issue of computing the non-linear matter power spectrum on mildly non-linear scales with efficient semi-analytic methods. We implemented M. Pietroni's Time Renormalization Group (TRG) method and its Dynamical 1-Loop (D1L) limit in a numerica ...

2011

A Framework for Numerical Simulations of Structure Formation

Claude Becker

In the absence of a full analytical treatment of nonlinear structure formation in the universe, numerical simulations provide the critical link between the properties of the underlying model and the features of the observed structures. Currently N-body sim ...

EPFL2011

Proposed new probe of modified gravity

Alexey Boyarsky, Oleg Ruchayskiy

We suggest a new efficient way to constrain a certain class of large scale modifications of gravity. We show that the scale-free relation between density and size of dark matter halos, predicted within the ACDM model with Newtonian gravity, gets modified i ...

2011

Dark goo: bulk viscosity as an alternative to dark energy

Julien Lesgourgues, Jean-Sébastien Gagnon

We present a simple (microscopic) model in which bulk viscosity plays a role in explaining the present acceleration of the universe. The effect of bulk viscosity on the Friedmann equations is to turn the pressure into an "effective" pressure containing the ...

2011

Universal Properties of Dark Matter Halos

Alexey Boyarsky, Oleg Ruchayskiy, Igor Tkachev

We discuss the universal relation between density and size of observed dark matter halos that was recently shown to hold on a wide range of scales, from dwarf galaxies to galaxy clusters. Predictions of cold dark matter (Lambda CDM) N-body simulations are ...

2010

Dark energy with non-adiabatic sound speed: initial conditions and detectability

Julien Lesgourgues

Assuming that the universe contains a dark energy fluid with a constant linear equation of state and a constant sound speed, we study the prospects of detecting dark energy perturbations using CMB data from Planck, cross-correlated with galaxy distribution ...

2010

Consistent Extension of Horava Gravity

Sergey Sibiryakov, Diego Blas Temino

We propose a natural extension of Horava's model for quantum gravity, which is free from the notorious pathologies of the original proposal. The new model endows the scalar graviton mode with a regular quadratic action and remains power-counting renormaliz ...

2010

CDMS stands for Constrained Dark Matter Singlet

Duccio Pappadopulo

Motivated by the two candidate Dark Matter events observed by the CDMS experiment, we consider a Constrained Dark Matter Singlet (CDMS) model that, with no free parameters, predicts the DM mass and the DM direct cross section to be in the range weakly favo ...

2010