Publications associées à Univers fractal

Heuristic Estimation of the Vacuum Energy Density of the Universe: Part II-Analysis Based on Frequency Domain Electromagnetic Radiation

In Part I of this paper, an inequality satisfied by the vacuum energy density of the universe was derived using an indirect and heuristic procedure. The derivation is based on a proposed thought experiment, according to which an electron is accelerated to ...

2024

XXXIV. The effect of linear redshift-space distortions in photometric galaxy clustering and its cross-correlation with cosmic shear

Frédéric Courbin, Georges Meylan, Gianluca Castignani, Maurizio Martinelli, Malte Tewes, Slobodan Ilic, Alessandro Pezzotta, Yi Wang, Richard Massey, Fabio Finelli, Marcello Farina

Context. The cosmological surveys that are planned for the current decade will provide us with unparalleled observations of the distribution of galaxies on cosmic scales, by means of which we can probe the underlying large-scale structure (LSS) of the Univ ...

Edp Sciences S A2024

Heuristic Estimation of the Vacuum Energy Density of the Universe: Part I—Analysis Based on Time Domain Electromagnetic Radiation

Farhad Rachidi-Haeri, Marcos Rubinstein

In this paper, an inequality satisfied by the vacuum energy density of the universe is derived using an indirect and heuristic procedure. The derivation is based on a proposed thought experiment, according to which an electron is accelerated to a constant ...

2023

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

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, Suresh Kumar, Hsin-Yu Chen

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

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, Yuting Wang

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

Signatures of the Primordial Universe from Its Emptiness: Measurement of Baryon Acoustic Oscillations from Minima of the Density Field

Jean-Paul Richard Kneib, Cheng Zhao, Yu Liang

Sound waves from the primordial fluctuations of the Universe imprinted in the large-scale structure, called baryon acoustic oscillations (BAOs), can be used as standard rulers to measure the scale of the Universe. These oscillations have already been detec ...

Amer Physical Soc2016

Inflation, LHC and the Higgs boson

Mikhail Chapochnikov

After the Higgs boson has been discovered, the Standard Model of particle physics became a confirmed theory, potentially valid up to the Planck scale and allowing to trace the evolution of the Universe from inflationary stage till the present days. We disc ...

World Scientific Publ Co Pte Ltd2015

Inflation, LHC and the Higgs boson

Mikhail Chapochnikov

After the Higgs boson has been discovered, the Standard Model of particle physics became a confirmed theory, potentially valid up to the Planck scale and allowing one to trace the evolution of the Universe from the inflationary stage till the present days. ...

Elsevier2015

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

Living beyond the edge: Higgs inflation and vacuum metastability

Mikhail Chapochnikov, Javier Rubio

The measurements of the Higgs mass and top Yukawa coupling indicate that we live in a very special universe, at the edge of the absolute stability of the electroweak vacuum. If fully stable, the Standard Model (SM) can be extended all the way up to the inf ...

American Physical Society2015

Cosmological implications of baryon acoustic oscillation measurements

Jean-Paul Richard Kneib, Johan Comparat, Timothée Guy Olivier Delubac, David Schlegel

We derive constraints on cosmological parameters and tests of dark energy models from the combination of baryon acoustic oscillation (BAO) measurements with cosmic microwave background (CMB) data and a recent reanalysis of Type Ia supernova (SN) data. In p ...

American Physical Society2015

Planck 2013 results. XXVI. Background geometry and topology of the Universe

Julien Lesgourgues, Jason Douglas McEwen, Fabio Finelli

The new cosmic microwave background (CMB) temperature maps from Planck provide the highest-quality full-sky view of the surface of last scattering available to date. This allows us to detect possible departures from the standard model of a globally homogen ...

Edp Sciences S A2014

Strongest model-independent bound on the lifetime of Dark Matter

Julien Lesgourgues, Benjamin Audren

Dark Matter is essential for structured formation in the late Universe so it must be stable on cosmological time scales. But how stable exactly? Only assuming decays into relativistic on particles, we report an otherwise model independent bound on the life ...

Iop Publishing Ltd2014

Higgs-Dilaton cosmology: Universality versus criticality

Mikhail Chapochnikov, Javier Rubio

The Higgs-Dilaton model is able to produce an early inflationary expansion followed by a dark energy dominated era responsible for the late time acceleration of the Universe. At tree level, the model predicts a small tensor-to-scalar ratio (0.0021

American Physical Society2014

Cosmological constraints on Lorentz violating dark energy

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

The role of Lorentz invariance as a fundamental symmetry of nature has been lately reconsidered in different approaches to quantum gravity. It is thus natural to study whether other puzzles of physics may be solved within these proposals. This may be the c ...

Iop Publishing Ltd2013

Cosmological lepton asymmetry with a nonzero mixing angle theta(13)

Julien Lesgourgues

While the baryon asymmetry of the Universe is nowadays well measured by cosmological observations, the bounds on the lepton asymmetry in the form of neutrinos are still significantly weaker. We place limits on the relic neutrino asymmetries using some of t ...

American Physical Society2012

EDGE: Explorer of diffuse emission and gamma-ray burst explosions

Matthias Finger, Alexey Boyarsky, Mikhail Chapochnikov, Oleg Ruchayskiy, Simone Campana

How structures of various scales formed and evolved from the early Universe up to present time is a fundamental question of astrophysical cosmology. EDGE (Piro et al., 2007) will trace the cosmic history of the baryons from the early generations of massive ...

2009