Publications de Julien Lesgourgues

Euclid: Validation of the MontePython forecasting tools

Frédéric Courbin, Georges Meylan, Jean-Luc Starck, Maurizio Martinelli, Julien Lesgourgues, Slobodan Ilic, Yi Wang, Richard Massey

Context. The Euclid mission of the European Space Agency will perform a survey of weak lensing cosmic shear and galaxy clustering in order to constrain cosmological models and fundamental physics. Aims. We expand and adjust the mock Euclid likelihoods of t ...

Edp Sciences S A2024

Cosmology intertwined: A review of the particle physics, astrophysics, and cosmology associated with the cosmological tensions and anomalies

Frédéric Courbin, Julien Lesgourgues, Mikhail Ivanov, Richard Irving Anderson, Fabio Finelli, Adriano Agnello, Jie Wang, Florian Niedermann, Emre Ozulker, Melissa Joseph

The standard Lambda Cold Dark Matter (Lambda CDM) cosmological model provides a good description of a wide range of astrophysical and cosmological data. However, there are a few big open questions that make the standard model look like an approximation to ...

ELSEVIER2022

REVIEW OF PARTICLE PHYSICS Particle Data Group

Olivier Schneider, Varun Sharma, Christophe Bauer, Greig Alan Cowan, Julien Lesgourgues, Riddhiman Sarkar, Vladimir Petrov, Florian Patrick Marie Daniel De la Barre De Nanteuil, Frank Zimmermann, Lorena Gonçalves de Alcântara e Freitas Krikler

The Review summarizes much of particle physics and cosmology. Using data from previous editions, plus 2,873 new measurements from 758 papers, we list, evaluate, and average measured properties of gauge bosons and the recently discovered Higgs boson, lepton ...

American Physical Society2018

A White Paper on keV sterile neutrino Dark Matter

Julien Lesgourgues, Antoine Pierre Emmanuel Alexis Merle, Alexey Boyarsky, Oleg Ruchayskiy, Laurent Gastaldo, Marco Drewes, Igor Tkachev, Jonathan Leon Wolf, Jan Hamann

We present a comprehensive review of keV-scale sterile neutrino Dark Matter, collecting views and insights from all disciplines involved - cosmology, astrophysics, nuclear, and particle physics - in each case viewed from both theoretical and experimental/o ...

Iop Publishing Ltd2017

Planck intermediate results XXX. The angular power spectrum of polarized dust emission at intermediate and high Galactic latitudes

Julien Lesgourgues, Fabio Finelli

The polarized thermal emission from diffuse Galactic dust is the main foreground present in measurements of the polarization of the cosmic microwave background (CMB) at frequencies above 100 GHz. In this paper we exploit the uniqueness of the Planck HFI po ...

EDP Sciences2016

Constraint on neutrino masses from SDSS-III/BOSS Ly alpha forest and other cosmological probes

Julien Lesgourgues, Arnaud Borde

We present constraints on the parameters of the ACDM cosmological model in the presence of massive neutrinos, using the one-dimensional Ly alpha forest power spectrum obtained with the Baryon Oscillation Spectroscopic Survey (BOSS) of the Sloan Digital Sky ...

Iop Publishing Ltd2015

Robustness of cosmic neutrino background detection in the cosmic microwave background

Julien Lesgourgues, Benjamin Audren

The existence of a cosmic neutrino background can be probed indirectly by CMB experiments, not only by measuring the background density of radiation in the universe, but also by searching for the typical signatures of the fluctuations of free-streaming spe ...

Iop Publishing Ltd2015

Neutrino masses and cosmology with Lyman-alpha forest power spectrum

Julien Lesgourgues, Arnaud Borde

We present constraints on neutrino masses, the primordial fluctuation spectrum from inflation, and other parameters of the ACDM model, using the one-dimensional Ly alpha-forest power spectrum measured by [1] from the Baryon Oscillation Spectroscopic Survey ...

Iop Publishing Ltd2015

Planck intermediate results XXIV. Constraints on variations in fundamental constants

Julien Lesgourgues, Fabio Finelli

Any variation in the fundamental physical constants, more particularly in the fine structure constant, a, or in the mass of the electron, me, affects the recombination history of the Universe and cause an imprint on the cosmic microwave background angular ...

EDP Sciences2015

Cosmological constraints on deviations from Lorentz invariance in gravity and dark matter

Julien Lesgourgues, Sergey Sibiryakov, Diego Blas Temino, Mikhail Ivanov, Benjamin Audren

We consider a scenario where local Lorentz invariance is violated by the existence of a preferred time direction at every space-time point. This scenario can arise in the context of quantum gravity and its description at low energies contains a unit time-l ...

Iop Publishing Ltd2015