Publications associées à Decoupling (cosmology)

SUNBIRD : a simulation-based model for full-shape density-split clustering

Combining galaxy clustering information from regions of different environmental densities can help break cosmological parameter degeneracies and access non-Gaussian information from the density field that is not readily captured by the standard two-point c ...

2024

Search for dark photon decays to μ+μ- at NA62

Radoslav Marchevski, Alina Kleimenova

The NA62 experiment at CERN, designed to study the ultra-rare decay K+ -> pi(+) nu(nu) over bar, has also collected data in beam-dump mode. In this configuration, dark photons may be produced by protons dumped on an absorber and reach a decay volume beginn ...

Springer Nature2023

GOGREEN: A critical assessment of environmental trends in cosmological hydrodynamical simulations at z approximate to 1

Pascale Jablonka, Hung-Hsu Chan

Recent observations have shown that the environmental quenching of galaxies at z & SIM; 1 is qualitatively different to that in the local Universe. However, the physical origin of these differences has not yet been elucidated. In addition, while low-redshi ...

OXFORD UNIV PRESS2023

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

Euclid : Effects of sample covariance on the number counts of galaxy clusters

Georges Meylan, Yi Wang, Richard Massey

Aims. We investigate the contribution of shot-noise and sample variance to uncertainties in the cosmological parameter constraints inferred from cluster number counts, in the context of the Euclid survey. ...

EDP SCIENCES S A2021

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

Constraints on dark matter to dark radiation conversion in the late universe with DES-Y1 and external data

Eduardo Sanchez, Jonathan Andrew Blazek

We study a phenomenological class of models where dark matter converts to dark radiation in the low redshift epoch. This class of models, dubbed DMDR, characterizes the evolution of comoving dark-matter density with two extra parameters, and may be able to ...

American Physical Society2021

Search for A ' -> mu(+)mu(-) Decays

Olivier Schneider, Aurelio Bay, Yiming Li, Guido Haefeli, Frédéric Blanc, Christoph Frei, Tatsuya Nakada, Michel De Cian, Luca Pescatore, Elena Graverini, Veronica Sølund Kirsebom, François Fleuret, Matthieu Philippe Luther Marinangeli, Minh Tâm Tran, Pietro Marino, Renato Quagliani, Federico Leo Redi, Federico Betti, Plamen Hristov Hopchev, Guido Andreassi, Aravindhan Venkateswaran, Violaine Bellée, Luis Miguel Garcia Martin, Maria Vieites Diaz, Vitalii Lisovskyi, Olivier Göran Girard, Axel Kuonen, Elisabeth Maria Niel, Preema Rennee Pais, Jian Wang, Pavol Stefko, Mingkui Wang, Tara Nanut, Zhirui Xu, Maria Elena Stramaglia, Yi Zhang, Vladimir Macko, Guillaume Max Pietrzyk, Lei Zhang, Sebastian Schulte, Lino Ferreira Lopes, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,

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

Search for the Dark Photon and the Dark Higgs Boson at Belle

Olivier Schneider, Mingkui Wang, Chao Wang, Tagir Aushev, Sun Hee Kim, Jun Yong Kim, Ji Hyun Kim, Donghyun Kim, Dipanwita Dutta, Xiao Wang

The dark photon A' and the dark Higgs boson h' are hypothetical constituents featured in a number of recently proposed dark sector models. Assuming prompt decays of both dark particles, we search for their production in the so-called Higgstrahlung channel ...

Amer Physical Soc2015

Planck intermediate results XXIV. Constraints on variations in fundamental constants

Julien Lesgourgues, Fabio Finelli

Any variation in the fundamental physical constants, more particularly in the fine structure constant, a, or in the mass of the electron, me, affects the recombination history of the Universe and cause an imprint on the cosmic microwave background angular ...

EDP Sciences2015

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

Separate constraints on early and late cosmology

Benjamin Audren

Since the public release of Planck data, several attempts have been made to explain the observed small tensions with other data sets, most of them involving an extension of the Lambda cold dark matter (Lambda CDM) model. We try here an alternative approach ...

Oxford Univ Press2014

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

Cosmological parameter estimation with large scale structure observations

Julien Lesgourgues, Ruth Durrer

We estimate the sensitivity of future galaxy surveys to cosmological parameters, using the redshift dependent angular power spectra of galaxy number counts, C-l(z(1), z(2)), calculated with all relativistic corrections at first order in perturbation theory ...

Iop Publishing Ltd2014

Conservative constraints on early cosmology with MONTE PYTHON

Julien Lesgourgues, Benjamin Audren

Models for the latest stages of the cosmological evolution rely on a less solid theoretical and observational ground than the description of earlier stages like BBN and recombination. As suggested in a previous work by Vonlanthen et al., it is possible to ...

Iop Publishing Ltd2013

The Cosmic Linear Anisotropy Solving System (CLASS) IV: efficient implementation of non-cold relics

Julien Lesgourgues

We present a new flexible, fast and accurate way to implement massive neutrinos, warm dark matter and any other non-cold dark matter relics in Boltzmann codes. For whatever analytical or numerical form of the phase-space distribution function, the optimal ...

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

Cosmological constraints on a light nonthermal sterile neutrino

Julien Lesgourgues

Although the MiniBooNE experiment has severely restricted the possible existence of light sterile neutrinos, a few anomalies persist in oscillation data, and the possibility of extra light species contributing as a subdominant hot (or warm) component is st ...

American Physical Society2009

The simulated 21 cm signal during the epoch of reionization: full modeling of the Ly-alpha pumping

Yves Revaz

The 21 cm emission of neutral hydrogen is the most promising probe of the epoch of reionization (EoR). In the next few years, the SKA pathfinders will provide statistical measurements of this signal, such as its power spectrum. Within one decade, SKA shoul ...

2009