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Publications associées (30)

Euclid preparation XXXVI. Modelling the weak lensing angular power spectrum

Maurizio Martinelli, Frédéric Courbin, Georges Meylan, Gianluca Castignani, Austin Chandler Peel

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

Swift : a modern highly parallel gravity and smoothed particle hydrodynamics solver for astrophysical and cosmological applications

Yves Revaz, Yannick Michael Bahé, Loïc Hausammann, Mladen Ivkovic

Numerical simulations have become one of the key tools used by theorists in all the fields of astrophysics and cosmology. The development of modern tools that target the largest existing computing systems and exploit state-of-the-art numerical methods and ...

2024

Euclid: Validation of the MontePython forecasting tools

Maurizio Martinelli, Frédéric Courbin, Georges Meylan, Julien Lesgourgues, Slobodan Ilic

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

The AGORA High-resolution Galaxy Simulations Comparison Project. V. Satellite Galaxy Populations in a Cosmological Zoom-in Simulation of a Milky Way-Mass Halo

Yves Revaz, Loïc Hausammann

We analyze and compare the satellite halo populations at z similar to 2 in the high-resolution cosmological zoom-in simulations of a 1012 M circle dot target halo (z = 0 mass) carried out on eight widely used astrophysical simulation codes (Art-I, Enzo, Ra ...

Iop Publishing Ltd2024

Cosmic void exclusion models and their impact on the distance scale measurements from large-scale structure

Jean-Paul Richard Kneib, Cheng Zhao, Daniel Felipe Forero Sanchez, Amélie Tamone, Andrei Variu

Baryonic Acoustic Oscillations (BAOs) studies based on the clustering of voids and matter tracers provide important constraints on cosmological parameters related to the expansion of the Universe. However, modelling the void exclusion effect is an importan ...

OXFORD UNIV PRESS2023

Fast correlation function calculator A high-performance pair-counting toolkit

Cheng Zhao

Context. A novel high-performance exact pair-counting toolkit called fast correlation function calculator (FCFC) is presented.Aims. With the rapid growth of modern cosmological datasets, the evaluation of correlation functions with observational and simula ...

EDP SCIENCES S A2023

Euclid preparation XXIV. Calibration of the halo mass function in λ(ν)CDM cosmologies

Maurizio Martinelli, Frédéric Courbin, Georges Meylan, Slobodan Ilic, Gianluca Castignani, Austin Chandler Peel

Euclid's photometric galaxy cluster survey has the potential to be a very competitive cosmological probe. The main cosmological probe with observations of clusters is their number count, within which the halo mass function (HMF) is a key theoretical quanti ...

EDP SCIENCES S A2023

Probing the nature of Dark Energy through the study of large scale structures using spectroscopic surveys and their simulations

Andrei Variu

Measurements of large-scale structure (LSS), as performed on the largest 3D map of over two million extragalactic sources from the Sloan Digital Sky Survey, together with measurements of the cosmic microwave background (CMB) anisotropies, are in complete a ...

EPFL2023

Scale invariant Einstein-Cartan gravity and flat space conformal symmetry

Mikhail Chapochnikov, Georgios Karananas, Sebastian Zell

We find the conditions under which scale-invariant Einstein-Cartan gravity with scalar matter fields leads to an approximate conformal invariance of the flat space particle theory up to energies of the order of the Planck mass. In the minimal setup, these ...

Springer Nature2023

Constraining the baryonic feedback with cosmic shear using the DES Year-3 small-scale measurements

Yi Zhang, Eduardo Sanchez, Jonathan Andrew Blazek, Binglun Yin

We use the small scales of the Dark Energy Survey (DES) Year-3 cosmic shear measurements, which are excluded from the DES Year-3 cosmological analysis, to constrain the baryonic feedback. To model the baryonic feedback, we adopt a baryonic correction model ...

Oxford Univ Press2022

Teaching machines how to find strongly lensed galaxies in cosmological sky surveys

Elodie Marie Charlène Savary

Analyzing gravitationally lensed objects enables a wide range of physical and cosmological applications, such as probing the dark matter content in galaxies and clusters or measuring the Universe's expansion rate. The precision of these applications can be ...

EPFL2022

The DESI N-body Simulation Project - II. Suppressing sample variance with fast simulations

Cheng Zhao, Yu Yu, Andrei Variu

Dark Energy Spectroscopic Instrument (DESI) will construct a large and precise three-dimensional map of our Universe. The survey effective volume reaches similar to 20 h(-3) Gpc(3). It is a great challenge to prepare high-resolution simulations with a much ...

OXFORD UNIV PRESS2022

Cosmological implications of the full shape of anisotropic clustering measurements in BOSS and eBOSS

Cheng Zhao

We present the analysis of the full shape of anisotropic clustering measurement from the extended Baryon Oscillation Spectroscopic Survey (eBOSS) quasar sample together with the combined galaxy sample from the Baryon Oscillation Spectroscopic Survey (BOSS) ...

OXFORD UNIV PRESS2022

KiDS and Euclid: Cosmological implications of a pseudo angular power spectrum analysis of KiDS-1000 cosmic shear tomography

Yi Wang, Georges Meylan, Huanyuan Shan

We present a tomographic weak lensing analysis of the Kilo Degree Survey Data Release 4 (KiDS-1000), using a new pseudo angular power spectrum estimator (pseudo-C-l) under development for the ESA Euclid mission. Over 21 million galaxies with shape informat ...

EDP SCIENCES S A2022

TOCOSMO VIII. A key test of systematics in the hierarchical method of time-delay cosmography

Frédéric Courbin

The largest source of systematic errors in the time-delay cosmography method likely arises from the lens model mass distribution, where an inaccurate choice of model could in principle bias the value of H-0. A Bayesian hierarchical framework has been propo ...

EDP SCIENCES S A2022

Copper-Phosphonate Lamella Intermediates Control the Shape of Colloidal Copper Nanocrystals

Raffaella Buonsanti, Jan Vávra, Dragos-Constantin Stoian, Valeria Mantella, Petru Pasquale Albertini, James Richard Pankhurst

Understanding the structure and behavior of intermediates in chemical reactions is key to developing greater control over the reaction outcome. This principle is particularly important in the synthesis of metal nanocrystals (NCs), where the reduction, nucl ...

2022

Euclid : Effects of sample covariance on the number counts of galaxy clusters

Yi Wang, Georges Meylan

Aims. We investigate the contribution of shot-noise and sample variance to uncertainties in the cosmological parameter constraints inferred from cluster number counts, in the context of the Euclid survey. ...

EDP SCIENCES S A2021

The completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: measurement of the BAO and growth rate of structure of the luminous red galaxy sample from the anisotropic correlation function between redshifts 0.6 and 1

Jean-Paul Richard Kneib, Cheng Zhao

We present the cosmological analysis of the configuration-space anisotropic clustering in the completed Sloan Digital Sky Survey IV extended Baryon Oscillation Spectroscopic Survey (eBOSS) Data Release 16 galaxy sample. This sample consists of luminous red ...

OXFORD UNIV PRESS2021

Controlling and leveraging small-scale information in tomographic galaxy-galaxy lensing

Jonathan Andrew Blazek

The tangential shear signal receives contributions from physical scales in the galaxy-matter correlation function well below the transverse scale at which it is measured. Since small scales are difficult to model, this non-locality has generally required s ...

OXFORD UNIV PRESS2020

The impact of the fiducial cosmology assumption on BAO distance scale measurements

Cheng Zhao

Standard analysis pipelines for measurements of Baryon Acoustic Oscillations (BAO) in galaxy surveys make use of a fiducial cosmological model to guide the data compression required to transform from observed redshifts and angles to the measured angular an ...

OXFORD UNIV PRESS2020