Publications associées à Découplage des neutrinos

MeV-scale seesaw and leptogenesis

Marco Drewes, Valerie Fiona Domcke, Michele Lucente

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

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

Probing sub-eV Dark Matter decays with PTOLEMY

Alexey Boyarsky, Kyrylo Bondarenko

When the Dark Matter mass is below the eV-scale, its cosmological occupation number exceeds the ones of photons from the cosmic microwave background as well as of relic neutrinos. If such Dark Matter decays to pairs of neutrinos, it implies that experiment ...

IOP PUBLISHING LTD2021

An allowed window for heavy neutral leptons below the kaon mass

Alexey Boyarsky, Kyrylo Bondarenko, Oleg Ruchayskiy, Inar Timiryasov, Juraj Klaric

The extension of the Standard Model with two gauge-singlet Majorana fermions can simultaneously explain two beyond-the-Standard-model phenomena: neutrino masses and oscillations, as well as the origin of the matter-antimatter asymmetry in the Universe. The ...

Springer Nature2021

The completed SDSS-IV extended baryon oscillation spectroscopic survey: pairwise-inverse probability and angular correction for fibre collisions in clustering measurements

Cheng Zhao, Anand Stéphane Raichoor, Amélie Tamone

The completed extended Baryon Oscillation Spectroscopic Survey (eBOSS) catalogues contain redshifts of 344 080 quasars at 0.8 < z < 2.2, 174 816 luminous red galaxies between 0.6 < z < 1.0, and 173 736 emission-line galaxies over 0.6 < z < 1.1 in order to ...

OXFORD UNIV PRESS2020

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

Robustness of cosmic neutrino background detection in the cosmic microwave background

Julien Lesgourgues, Benjamin Audren

The existence of a cosmic neutrino background can be probed indirectly by CMB experiments, not only by measuring the background density of radiation in the universe, but also by searching for the typical signatures of the fluctuations of free-streaming spe ...

Iop Publishing Ltd2015

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

Design and packaging of a highly integrated microreactor system for high-temperature on-board hydrogen production

John Richard Thome, Paul Muralt, Thomas Maeder, Navid Borhani, Bo Jiang, Dimos Poulikakos

Highlights • A “plug-and-play” microreaction system for high-temperature reactions (>500 °C). • Efficient thermal decoupling for using standard electrical/fluidic connections. • Automatic and accurate temperature control for calorimetric measurements. • A ...

Elsevier2015

The effective gravitational decoupling between dark matter and the CMB

Julien Lesgourgues, Luc Voruz

We present a detailed and self-contained analytical derivation of the evolution of sub-horizon cosmological perturbations before decoupling, based on previous work by S. Weinberg. These solutions are valid in the minimal Lambda CDM scenario, to first order ...

Iop Publishing Ltd2014

Neutrino cosmology and Planck

Julien Lesgourgues

Relic neutrinos play an important role in the evolution of the Universe, modifying some of the cosmological observables. We summarize the main aspects of cosmological neutrinos and describe how the precision of present cosmological data can be used to lear ...

Iop Publishing Ltd2014

CMB power spectra and likelihood

Julien Lesgourgues, Fabio Finelli

This paper presents the Planck 2013 likelihood, a complete statistical description of the two-point correlation function of the CMB temperature fluctuations that accounts for all known relevant uncertainties, both instrumental and astrophysical in nature. ...

Edp Sciences S A2014

Using the CMB angular power spectrum to study Dark Matter-photon interactions

Julien Lesgourgues

In this paper, we explore the impact of Dark Matter-photon interactions on the CMB angular power spectrum. Using the one-year data release of the Planck satellite, we derive an upper bound on the Dark Matter-photon elastic scattering cross section of sigma ...

Iop Publishing Ltd2014

Planck 2013 results. XVI. Cosmological parameters

Julien Lesgourgues, Xin Chen, Fabio Finelli, Jan Hamann

This paper presents the first cosmological results based on Planck measurements of the cosmic microwave background (CMB) temperature and lensing-potential power spectra. We find that the Planck spectra at high multipoles (l greater than or similar to 40) a ...

Edp Sciences S A2014

Weak scale baryogenesis in a supersymmetric scenario with R-parity violation

We investigate the connection between R-parity violation (RPV) in supersymmetric models and Baryogenesis. First we discuss in detail the assumptions of a theorem by Nanopoulos and Weinberg on the CP asymmetry generated from the decay of massive particles. ...

Springer Nature2014

Planck 2013 results. XII. Diffuse component separation

Julien Lesgourgues, Xin Chen, Fabio Finelli

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

Matter and antimatter in the universe

Mikhail Chapochnikov, Marco Drewes, Laurent Canetti

We review observational evidence for a matter-antimatter asymmetry in the early universe, which leads to the remnant matter density we observe today. We also discuss bounds on the presence of antimatter in the present-day universe, including the possibilit ...

Iop Publishing Ltd2012

Background studies for acoustic neutrino detection at the South Pole

Shirit Cohen, Mathieu Ribordy, Matthias Wolf, Xiaoxia Bai

The detection of acoustic signals from ultra-high energy neutrino interactions is a promising method to measure the flux of cosmogenic neutrinos expected on Earth. The energy threshold for this process depends strongly on the absolute noise level in the ta ...

2012

Symmetric and antisymmetric exchange anisotropies in quasi-one-dimensional CuSe2O5 as revealed by ESR

Helmuth Berger

We present an electron spin resonance (ESR) study of a single-crystalline spin chain system CuSe2O5 in the frequency range between 9 and 430 GHz. In a wide temperature range above the Neel temperature T-N = 17 K we observe a strong and anisotropic frequenc ...

2011

Cosmological parameters from large scale structure - geometric versus shape information

Julien Lesgourgues, Jan Hamann

The matter power spectrum as derived from large scale structure (LSS) surveys contains two important and distinct pieces of information: an overall smooth shape and the imprint of baryon acoustic oscillations (BAO). We investigate the separate impact of th ...

2010