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Concept

Amas de la Balle

Publications associées (32)

DeepSphere: Efficient spherical convolutional neural network with HEALPix sampling for cosmological applications

Nathanaël Perraudin, Michaël Defferrard

Convolutional Neural Networks (CNNs) are a cornerstone of the Deep Learning toolbox and have led to many breakthroughs in Artificial Intelligence. So far, these neural networks (NNs) have mostly been developed for regular Euclidean domains such as those su ...

ELSEVIER SCIENCE BV2019

Observable tests of self-interacting dark matter in galaxy clusters: BCG wobbles in a constant density core

David Richard Harvey

Models of cold dark matter (CDM) predict that the distribution of dark matter in galaxy clusters should be cuspy, centrally concentrated. Constant density cores would be strong evidence for beyond CDM physics, such as self-interacting dark matter (SIDM). A ...

OXFORD UNIV PRESS2019

Boosting the dark matter signal with Coulomb resonances

Rakhi Nandalal Mahbubani, Kin Shanho Eliaou Mimouni

We show that the presence of nearby Coulombic resonances at finite energy could lead to the enhancement of the dark matter annihilation cross section at specific non-zero velocities correlated with the mass splitting between the dark matter pair and that o ...

IOP PUBLISHING LTD2019

Advanced gravitational lensing techniques for precision cosmology

Markus Rexroth

Gravitational lensing - the deflection of light by gravity - has greatly developed since its famous first observation in 1919, which validated Einstein's General Theory of Relativity. The strength of this effect does not depend on the nature of the mass wh ...

EPFL2018

Machine-learning methods for weak lensing analysis of the ESA Euclid sky survey

Thibault Adrien Kuntzer

A clear picture has emerged from the last three decades of research: our Universe is expanding at an accelerated rate. The cause of this expansion remains elusive, but in essence acts as a repulsive force. This so-called dark energy represents about 69% of ...

EPFL2018

Mapping substructure in the HST Frontier Fields cluster lenses and in cosmological simulations

Jean-Paul Richard Kneib, Hakim Atek

We map the lensing-inferred substructure in the first three clusters observed by the Hubble Space Telescope Frontier Fields (HSTFF) Initiative: Abell 2744 (z = 0.308), MACSJ 0416, (z = 0.396) and MACSJ 1149 (z = 0.543). Statistically resolving dark matter ...

Oxford Univ Press2017

A test for skewed distributions of dark matter, and a possible detection in galaxy cluster Abell 3827

Frédéric Courbin, David Richard Harvey, Rémy Elie Joseph

Simulations of self-interacting dark matter predict that dark matter should lag behind galaxies during a collision. If the interaction is mediated by a high-mass force carrier, the distribution of dark matter can also develop asymmetric dark matter tails. ...

Oxford Univ Press2017

Stellar-to-halo mass relation of cluster galaxies

Jean-Paul Richard Kneib, Huanyuan Shan

In the formation of galaxy groups and clusters, the dark matter haloes containing satellite galaxies are expected to be tidally stripped in gravitational interactions with the host. We use galaxy-galaxy weak lensing to measure the average mass of dark matt ...

Oxford Univ Press2017

Looking for dark matter trails in colliding galaxy clusters

Jean-Paul Richard Kneib, David Richard Harvey

If dark matter interacts, even weakly, via non-gravitational forces, simulations predict that it will be preferentially scattered towards the trailing edge of the halo during collisions between galaxy clusters. This will temporarily create a non-symmetric ...

Oxford Univ Press2017

CODEX weak lensing: concentration of galaxy clusters at z similar to 0.5

Jean-Paul Richard Kneib, Huanyuan Shan

We present a stacked weak-lensing analysis of 27 richness selected galaxy clusters at 0.40

Oxford Univ Press2017

Polarization of photons emitted by decaying dark matter

Mikhail Chapochnikov, Anna Tokareva

Radiatively decaying dark matter may be searched through investigating the photon spectrum of galaxies and galaxy clusters. We explore whether the properties of dark matter can be constrained through the study of a polarization state of emitted photons. St ...

Elsevier2017

The Bullet cluster at its best: weighing stars, gas, and dark matter

Jean-Paul Richard Kneib, Danuta Janina Paraficz

Aims. We present a new strong lensing mass reconstruction of the Bullet cluster (1E 0657-56) at z = 0 : 296, based on WFC3 and ACS HST imaging and VLT/FORS2 spectroscopy. The strong lensing constraints underwent substantial revision compared to previously ...

Edp Sciences S A2016