Concept

Univers de Milne

Publications associées (11)

Euclid preparation XXXVI. Modelling the weak lensing angular power spectrum

Frédéric Courbin, Georges Meylan, Gianluca Castignani, Austin Chandler Peel, Maurizio Martinelli, Yi Wang, Richard Massey, Fabio Finelli, Marcello Farina

This work considers which higher order modeling e ffects on the cosmic shear angular power spectra must be taken into account for Euclid. We identified the relevant terms and quantified their individual and cumulative impact on the cosmological parameter i ...

Edp Sciences S A2024

Effective photon mass and (dark) photon conversion in the inhomogeneous Universe

Kyrylo Bondarenko

Photons traveling cosmological distances through the inhomogeneous Universe experience a great variation in their in-medium induced effective mass. Using the EAGLE suite of hydrodynamical simulations, we infer the free electron distribution and thereby the ...

IOP PUBLISHING LTD2020

Constraining dark photons and their connection to 21 cm cosmology with CMB data

Kyrylo Bondarenko

In the inhomogeneous Universe, the cosmological conversion of dark photons into ordinary photons (and vice versa) may happen at a great number of resonance redshifts. This alters the CMB observed energy spectrum and degree of small-scale anisotropies. We u ...

2020

H0LiCOW-XIII. A 2.4 per cent measurement of H-0 from lensed quasars: 5.3 sigma tension between early- and late-Universe probes

Frédéric Courbin, Georges Meylan, Martin Raoul Robert Millon, Hung-Hsu Chan, Vivien François Bonvin, Olga Tihhonova, Adriano Agnello

We present a measurement of the Hubble constant (H-0) and other cosmological parameters from a joint analysis of six gravitationally lensed quasars with measured time delays. All lenses except the first are analysed blindly with respect to the cosmological ...

OXFORD UNIV PRESS2020

H0LiCOW-I. H-0 Lenses in COSMOGRAIL's Wellspring: program overview

Frédéric Courbin, Georges Meylan, Malte Tewes, Vivien François Bonvin, Olga Tihhonova, Adriano Agnello

Strong gravitational lens systems with time delays between the multiple images allow measurements of time-delay distances, which are primarily sensitive to the Hubble constant that is key to probing dark energy, neutrino physics and the spatial curvature o ...

Oxford Univ Press2017

On the dark radiation problem in the axiverse

Anna Tokareva

String scenarios generically predict that we live in a so called axiverse: the Universe with about a hundred of light axion species which are decoupled from the Standard Model particles. However, the axions can couple to the inflaton which leads to their p ...

Iop Publishing Ltd2017

We consider the classical evolution of the inflaton field and the Hubble parameter in homogeneous and isotropic single-field inflation models. Under an extremely broad assumption, we show that the Universe generically emerges from an initial singularity in ...

American Physical Society2014

Optimal polarisation equations in FLRW universes

Julien Lesgourgues

This paper presents the linearised Boltzmann equation for photons for scalar, vector and tensor perturbations in flat, open and closed FLRW cosmologies. We show that E- and B-mode polarisation for all types can be computed using only a single hierarchy. Th ...

Iop Publishing Ltd2013

COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses XIV. Time delay of the doubly lensed quasar SDSS J1001+5027

Frédéric Courbin, Georges Meylan, Malte Tewes

This paper presents optical R-band light curves and the time delay of the doubly imaged gravitationally lensed quasar SDSS J1001+5027 at a redshift of 1.838. We have observed this target for more than six years, between March 2005 and July 2011, using the ...

Edp Sciences S A2013

Cosmological Perturbation Theory

Sylvain Bréchet

Firstly, a dynamical analysis of adiabatic perturbations of a perfect fluid is performed to first-order about a general FLRW background using the 1 + 3 covariant and gauge-invariant formalism. The 1 + 3 covariant analog of the Mukhanov-Sasaki and Grishchuk ...

University of Cambridge2009

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