Concept

Problème de l'horizon

Publications associées (32)

Euclid: The search for primordial features

Yiming Li, Frédéric Courbin, Georges Meylan

Primordial features, in particular oscillatory signals, imprinted in the primordial power spectrum of density perturbations represent a clear window of opportunity for detecting new physics at high-energy scales. Future spectroscopic and photometric measur ...

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

Gravitational wave signal from primordial magnetic fields in the Pulsar Timing Array frequency band

Andrii Neronov

The NANOGrav, Parkes, European, and International Pulsar Timing Array (PTA) Collaborations have reported evidence for a common-spectrum process that can potentially correspond to a stochastic gravitational wave background (SGWB) in the 1-100 nHz frequency ...

American Physical Society2022

The completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: measurement of the BAO and growth rate of structure of the emission line galaxy sample from the anisotropic power spectrum between redshift 0.6 and 1.1

Cheng Zhao, Anand Stéphane Raichoor, Amélie Tamone, Claudio Gorgoni

We analyse the large-scale clustering in Fourier space of emission line galaxies (ELG) from the Data Release 16 of the Sloan Digital Sky Survey IV extended Baryon Oscillation Spectroscopic Survey. The ELG sample contains 173736 galaxies covering 1170deg(2) ...

OXFORD UNIV PRESS2021

New constraints on the mass of fermionic dark matter from dwarf spheroidal galaxies

Alexey Boyarsky, Diego Blas Temino, Kyrylo Bondarenko

Dwarf spheroidal galaxies are excellent systems to probe the nature of fermionic dark matter due to their high observed dark matter phase-space density. In this work, we review, revise, and improve upon previous phase-space considerations to obtain lower b ...

OXFORD UNIV PRESS2021

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

MeV-scale seesaw and leptogenesis

Marco Drewes, Valerie Fiona Domcke

We study the type-I seesaw model with three right-handed neutrinos and Majorana masses below the pion mass. In this mass range, the model parameter space is not only strongly constrained by the requirement to explain the light neutrino masses, but also by ...

Springer Nature2021

Effective photon mass and (dark) photon conversion in the inhomogeneous Universe

Kyrylo Bondarenko

Photons traveling cosmological distances through the inhomogeneous Universe experience a great variation in their in-medium induced effective mass. Using the EAGLE suite of hydrodynamical simulations, we infer the free electron distribution and thereby the ...

IOP PUBLISHING LTD2020

Very massive tracers and higher derivative biases

Valentin Mauerhofer

Most of the upcoming cosmological information will come from analyzing the clustering of the Large Scale Structures (LSS) of the universe through LSS or CMB observations. It is therefore essential to be able to understand their behavior with exquisite prec ...

2020

Constraining dark photons and their connection to 21 cm cosmology with CMB data

Kyrylo Bondarenko

In the inhomogeneous Universe, the cosmological conversion of dark photons into ordinary photons (and vice versa) may happen at a great number of resonance redshifts. This alters the CMB observed energy spectrum and degree of small-scale anisotropies. We u ...

2020

Effective field theory for acoustic and pseudoacoustic phonons in solids

Angelo Esposito

We present a relativistic effective field theory for the interaction between acoustic and gapped phonons in the limit of a small gap. We show that, while the former are the Goldstone modes associated with the spontaneous breaking of spacetime symmetries, t ...

American Physical Society2020

Ability of LIGO and LISA to probe the equation of state of the early Universe

Daniel Garcia Figueroa

The expansion history of the Universe between the end of inflation and the onset of radiation-domination (RD) is currently unknown. If the equation of state during this period is stiffer than that of radiation, w > 1/3, the gravitational wave (GW) backgrou ...

IOP PUBLISHING LTD2019

Anytime Heuristic for Weighted Matching Through Altruism-Inspired Behavior

Boi Faltings, Aris Filos Ratsikas, Panayiotis Danassis

We present a novel anytime heuristic (ALMA), inspired by the human principle of altruism, for solving the assignment problem. ALMA is decentralized, completely uncoupled, and requires no communication between the participants. We prove an upper bound on th ...

2019

Towards More Accurate Radio Telescope Images

Paul Hurley, Matthieu Martin Jean-André Simeoni

Radio interferometry usually compensates for high levels of noise in sensor/antenna electronics by throwing data and energy at the problem: observe longer, then store and process it all. We propose instead a method to remove the noise explicitly before ima ...

IEEE2018

Polarised black holes in ABJM

João Miguel Augusto Penedones Fernandes

We numerically construct asymptotically AdS(4) solutions to Einstein-Maxwell-dilaton theory. These have a dipolar electrostatic potential turned on at the conformal boundary S-2 x R-t. We find two classes of geometries: AdS soliton solutions that encode th ...

Springer Nature2017

Exploring cosmic homogeneity with the BOSS DR12 galaxy sample

Timothée Guy Olivier Delubac

In this study, we probe the transition to cosmic homogeneity in the Large Scale Structure (LSS) of the Universe using the CMASS galaxy sample of BOSS spectroscopic survey which covers the largest effective volume to date, 3 h(-3) Gpc(3) at 0.43

Iop Publishing Ltd2017

Measurement of baryon acoustic oscillation correlations at z=2.3 with SDSS DR12 Ly alpha-Forests

Timothée Guy Olivier Delubac

Here, we use flux-transmission correlations in Ly alpha forests to measure the imprint of baryon acoustic oscillations (BAO). The study uses spectra of 157,783 quasars in the redshift range 2.1

Edp Sciences S A2017

The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: tomographic BAO analysis of DR12 combined sample in configuration space

Jean-Paul Richard Kneib

We perform a tomographic baryon acoustic oscillations (BAOs) analysis using the two-point galaxy correlation function measured from the combined sample of Baryon Oscillation Spectroscopic Survey Data Release 12 (BOSS DR12), which covers the redshift range ...

Oxford Univ Press2017

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

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

Higgs inflation and vacuum stability

Javier Rubio

Inflation is nowadays a well-established paradigm consistent with all the observations. The precise nature of the inflaton is however unknown and its role could be played by any candidate able to imitate a scalar condensate in the slow-roll regime. The dis ...

Iop Publishing Ltd2015