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Concept

Gravité entropique

Publications associées (23)

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

An Unbiased Method of Measuring the Ratio of Two Data Sets

Jean-Paul Richard Kneib, Huanyuan Shan

In certain cases of astronomical data analysis, the meaningful physical quantity to extract is the ratio R between two data sets. Examples include the lensing ratio, the interloper rate in spectroscopic redshift samples, and the decay rate of gravitational ...

IOP Publishing Ltd2023

Void Lensing in Cubic Galileon Gravity

Cheng Zhao, Huanyuan Shan, Jiaxi Yu, Qiao Wang

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

Probing gravity with the DES-CMASS sample and BOSS spectroscopy

Eduardo Sanchez, Jonathan Andrew Blazek

The DES-CMASS sample (DMASS) is designed to optimally combine the weak lensing measurements from the Dark Energy Survey (DES) and redshift-space distortions (RSD) probed by the CMASS galaxy sample from the Baryonic Oscillation Spectroscopic Survey. In this ...

2022

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

TDCOSMO. IV. Hierarchical time-delay cosmography - joint inference of the Hubble constant and galaxy density profiles

Frédéric Courbin, Martin Raoul Robert Millon, Aymeric Alexandre Galan

The H0LiCOWcollaboration inferred via strong gravitational lensing time delays a Hubble constant value of H0 = 73 :3+1:7 1:8 km s 1 Mpc 1, describing deflector mass density profiles by either a power-law or stars (constant mass-to-light ratio) plus standar ...

EDP SCIENCES S A2020

Semiclassical S-matrix and black hole entropy in dilaton gravity

Sergey Sibiryakov

We use complex semiclassical method to compute scattering amplitudes of a point particle in dilaton gravity with a boundary. This model has nonzero minimal black hole mass M-cr. We find that at energies below M-cr the particle trivially scatters off the bo ...

Springer Nature2020

Inflationary perturbations with Lifshitz scaling

Sergey Sibiryakov

Instead of Lorentz invariance, gravitational degrees of freedom may obey Lifshitz scaling at high energies, as it happens in Horava's proposal for quantum gravity. We study consequences of this proposal for the spectra of primordial perturbations generated ...

IOP PUBLISHING LTD2019

Sparse Lens Inversion Technique (SLIT): lens and source separability from linear inversion of the source reconstruction problem

Frédéric Courbin, Rémy Elie Joseph

Strong gravitational lensing offers a wealth of astrophysical information on the background source it affects, provided the lensed source can be reconstructed as if it was seen in the absence of lensing. In the present work, we illustrate how sparse optimi ...

EDP SCIENCES S A2019

Experimental results of gravity currents travelling over a fissured bed

Anton Schleiss, Mário Jorge Rodrigues Pereira Da Franca, Sara Venuleo

Gravity currents are geophysical flows having large impact on human life and on the environment. The need to prevent and mitigate their negative consequences justifies the multitude of studies carried out to understand their physics. However little has bee ...

2019

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

Yi Zhang, Eduardo Sanchez, Jonathan Andrew Blazek

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

Towards a non-perturbative approach to the Hierarchy problem

Andrey Shkerin

In this report, based on [1], we suggest that the hierarchy between the Electroweak (EW) and the Planck scales can emerge due to a nonperturbative effect that relates low-energy and strong-gravity physics. In this mechanism, the EW scale results from an ex ...

EDP SCIENCES2018

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

EXPERIMENTAL RESULTS ON SEDIMENT ENTRAINMENT BY GRAVITY CURRENTS

Anton Schleiss, Mário Jorge Rodrigues Pereira Da Franca, Carmelo Juez Jiménez, Jessica Zordan

Gravity currents are geophysical flows responsible of the distal transport of high volumes of sediments. In particular, turbidity currents, a form of gravity currents where sediments in suspension confer the buoyancy that ignites the flow, are the main mec ...

2017

The extended Baryon Oscillation Spectroscopic Survey: a cosmological forecast

Jean-Paul Richard Kneib, Timothée Guy Olivier Delubac

We present a science forecast for the extended Baryon Oscillation Spectroscopic Survey (eBOSS) survey. Focusing on discrete tracers, we forecast the expected accuracy of the baryonic acoustic oscillation (BAO), the redshift-space distortion (RSD) measureme ...

Oxford Univ Press2016

Composite charge 8/3 resonances at the LHC

Francesco Riva

In composite Higgs models with partial compositeness, the small value of the observed Higgs mass implies the existence of light fermionic resonances, the top partners, whose quantum numbers are determined by the symmetry (and symmetry breaking) structure o ...

Springer Nature2014

Planck 2013 results. XII. Diffuse component separation

Xin Chen, Julien Lesgourgues

Planck has produced detailed all-sky observations over nine frequency bands between 30 and 857 GHz. These observations allow robust reconstruction of the primordial cosmic microwave background (CMB) temperature fluctuations over nearly the full sky, as wel ...

Edp Sciences S A2014

Removal of two large-scale cosmic microwave background anomalies after subtraction of the integrated Sachs-Wolfe effect

Anaïs Marie Rassat

Context. Although there is currently a debate over the significance of the claimed large-scale anomalies in the cosmic microwave background (CMB), their existence is not totally dismissed. In parallel to the debate over their statistical significance, rece ...

Edp Sciences S A2013

Phase Analysis of the Stretching Cycles of the Head of Unsteady Gravity Currents Developing over Smooth and Rough Beds

Mário Jorge Rodrigues Pereira Da Franca, Helena Isabel Dos Santos Nogueira

Gravity currents are buoyancy driven flows occurring spontaneously in nature or resulting from human intervention. Examples of gravity currents in the water are oceanic fronts, resulting from differences in temperature and salinity, and turbidity currents ...

Chengdu University Press2013

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