Publications associées à Histoire de la relativité générale

Void Lensing in Cubic Galileon Gravity

Jiaxi Yu, Cheng Zhao, Huanyuan Shan, Qiao Wang, Jun Zhang

Weak-lensing studies via cosmic voids are a promising probe of modified gravity (MG). The excess surface mass density (ESD) is widely used as a lensing statistic in weak-lensing research. In this paper, we use the ray-tracing method to study the ESD around ...

IOP Publishing Ltd2023

Coupling metric-affine gravity to a Higgs-like scalar field

Sebastian Zell

General relativity (GR) exists in different formulations. They are equivalent in pure gravity but generically lead to distinct predictions once matter is included. After a brief overview of various versions of GR, we focus on metric-affine gravity, which a ...

American Physical Society2022

A simple theoretical model for estimating the frequency characteristics of black hole mergers

Roberto Guarino

Gravitational waves, despite predicted within the Theory of General Relativity about a century ago, were observed experi-mentally only in the last few years, thanks to the recent advances of the LIGO and Virgo detectors. In this work, we introduce a simple ...

2022

A proof of the instability of AdS for the Einstein-massless Vlasov system

Georgios Moschidis

In recent years, the conjecture on the instability of Anti-de Sitter spacetime, put forward by Dafermos-Holzegel (Dynamic instability of solitons in 4 + 1 dimesnional gravity with negative cosmological constant, 2006. https://www.dpmms.cam.ac.uk/similar to ...

SPRINGER HEIDELBERG2022

Cosmology with Large Scale Structures using Massive Spectroscopic Surveys

Amélie Tamone

Spectroscopic surveys aim to map large fractions of the Universe to study the Large Scale Structures (LSS). LSS evolution traces the distribution of matter as a result of the tension between the expansion of the Universe and the gravitational forces, which ...

EPFL2022

Testing general relativity on cosmological scales at redshift z similar to 1.5 with quasar and CMB lensing

Cheng Zhao

We test general relativity (GR) at the effective redshift (z) over tilde similar to 1.5 by estimating the statistic E-G, a probe of gravity, on cosmological scales 19 - 190 h(-1)Mpc. This is the highest redshift and largest scale estimation of E-G so far. ...

OXFORD UNIV PRESS2021

Euclid preparation: IX. EuclidEmulator2-power spectrum emulation with massive neutrinos and self-consistent dark energy perturbations

Georges Meylan, Gianluca Castignani, Yi Wang, Richard Massey, Fabio Finelli

We present a new, updated version of the EuclidEmulator (called EuclidEmulator2), a fast and accurate predictor for the nonlinear correction of the matter power spectrum. 2 per cent level accurate emulation is now supported in the eight-dimensional paramet ...

OXFORD UNIV PRESS2021

Completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: Cosmological implications from two decades of spectroscopic surveys at the Apache Point Observatory

Jean-Paul Richard Kneib, Andrei Variu, Zheng Zheng, Cheng Zhao, Anand Stéphane Raichoor, Johan Comparat, Amélie Tamone, Yuting Wang

We present the cosmological implications from final measurements of clustering using galaxies, quasars, and Ly alpha forests from the completed Sloan Digital Sky Survey (SDSS) lineage of experiments in large-scale structure. These experiments, composed of ...

American Physical Society2021

Inconsistency of an inflationary sector coupled only to Einstein gravity

Daniel Garcia Figueroa

From a model-building perspective, the inflationary sector might very well have no direct couplings to other species, apart from inevitable gravitational interactions. Within the context of General Relativity, a thermal universe can still emerge after infl ...

IOP PUBLISHING LTD2019

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

Eduardo Sanchez, Jonathan Andrew Blazek, Yi Zhang

We present constraints on extensions of the minimal cosmological models dominated by dark matter and dark energy, Lambda CDM and wCDM, by using a combined analysis of galaxy clustering and weak gravitational lensing from the first-year data of the Dark Ene ...

American Physical Society2019

Testing gravity with galaxy-galaxy lensing and redshift-space distortions using CFHT-Stripe 82, CFHTLenS, and BOSS CMASS datasets

Jean-Paul Richard Kneib, Johan Comparat, Huanyuan Shan

The combination of galaxy-galaxy lensing (GGL) and redshift space distortion of galaxy clustering (RSD) is a privileged technique to test general relativity predictions and break degeneracies between the growth rate of structure parameter f and the amplitu ...

EDP Sciences2019

What do gravitons say about (unimodular) gravity?

Mario Herrero Valea

We revisit the problem of constraining the weak field limit of the gravitational lagrangian from S-matrix properties. From unitarity and Lorentz invariance of the S-matrix of massless gravitons, we derive on-shell gauge invariance to consist on the transve ...

Springer Nature2018

Gravity, scale invariance and the hierarchy problem

Mikhail Chapochnikov, Andrey Shkerin

Combining the quantum scale invariance with the absence of new degrees of freedom above the electroweak scale leads to stability of the latter against perturbative quantum corrections. Nevertheless, the hierarchy between the weak and the Planck scales rema ...

Springer Nature2018

Sparse Linear Inversion for Strong Gravitational Lenses Reconstruction, Component Separation from Morphological Component Analysis with Multiple Discrimination Criteria

Rémy Elie Joseph

Strong gravitational is a natural phenomenon that produces distorted images of distant galaxies due to massive galaxies or clusters, called deflectors or lenses, lying along the line of sight. Due to the mass of the deflector, and as a result of general re ...

EPFL2018

Emergence of Friedmann Equation of Cosmology of a Flat Universe from the Time-Energy Uncertainty Principle

Farhad Rachidi-Haeri

Friedmann equation of cosmology is based on the field equations of general relativity. Its derivation is straight-forward once the Einstein’s field equations are given and the derivation is independent of quantum mechanics. In this paper, it is shown that ...

2017

Electroweak vacuum stability in the Higgs-Dilaton theory

Andrey Shkerin

We study the stability of the Electroweak (EW) vacuum in a scale-invariant extension of the Standard Model and General Relativity, known as a Higgs-Dilaton theory. The safety of the EW vacuum against possible transition towards another vacuum is a necessar ...

Springer Nature2017

Lensing is low: cosmology, galaxy formation or new physics?

Huanyuan Shan

We present high signal-to-noise galaxy-galaxy lensing measurements of the Baryon Oscillation Spectroscopic Survey constant mass (CMASS) sample using 250 deg(2) of weak-lensing data from Canada-France-Hawaii Telescope Lensing Survey and Canada-France-Hawaii ...

Oxford Univ Press2017

Precise measurements of time delays in gravitationally lensed quasars for competitive and independent determination of the Hubble constant

Vivien François Bonvin

During these last decades, by virtue of observations, the Standard Cosmological Model has emerged, providing a description of the Universe's evolution using a minimal set of independent constraints - the cosmological parameters. Among them is the expansion ...

EPFL2017

Scale-invariant alternatives to general relativity. II. Dilaton properties

Mikhail Chapochnikov, Georgios Karananas

In the present paper, we revisit gravitational theories which are invariant under TDiffs-transverse (volume-preserving) diffeomorphisms and global scale transformations. It is known that these theories can be rewritten in an equivalent diffeomorphism-invar ...

American Physical Society2016

The Sdss-Iv Extended Baryon Oscillation Spectroscopic Survey: Overview And Early Data

Jean-Paul Richard Kneib, Anand Stéphane Raichoor, Timothée Guy Olivier Delubac, Zheng Zheng, Cheng Zhao, Johan Comparat, David Schlegel, Yuting Wang, Pierre Laurent, Cheng Li, Yu Liang

In a six-year program started in 2014 July, the Extended Baryon Oscillation Spectroscopic Survey (eBOSS) will conduct novel cosmological observations using the BOSS spectrograph at Apache Point Observatory. These observations will be conducted simultaneous ...

Iop Publishing Ltd2016