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Concept

Pôle céleste

Publications associées (21)

Where is M-theory in the space of scattering amplitudes?

João Miguel Augusto Penedones Fernandes, Andrea Guerrieri

We use the S-matrix bootstrap to carve out the space of unitary, analytic, crossing symmetric and supersymmetric graviton scattering amplitudes in nine, ten and eleven dimensions. We extend and improve the numerical methods of our previous work in ten dime ...

Springer Nature2023

Highly Active Ice‐Nucleating Particles at the Summer North Pole

Julia Schmale

The amount of ice versus supercooled water in clouds is important for their radiative properties and role in climate feedbacks. Hence, knowledge of the concentration of ice-nucleating particles (INPs) is needed. Generally, the concentrations of INPs are fo ...

2022

Graph Spectral Clustering of Convolution Artefacts in Radio Interferometric Images

Paul Hurley, Matthieu Martin Jean-André Simeoni

The starting point for deconvolution methods in radioastronomy is an estimate of the sky intensity called a dirty image. These methods rely on the telescope point-spread function so as to remove artefacts which pollute it. In this work, we show that the in ...

IEEE2019

Evolution of critical buckling conditions in imperfect bilayer shells through residual swelling

Pedro Miguel Nunes Pereira de Almeida Reis, Matteo Pezzulla, Dong Yan, Anna Lee

We propose and investigate a minimal mechanism that makes use of differential swelling to modify the critical buckling conditions of elastic bilayer shells, as measured by the knockdown factor. Our shells contain an engineered defect at the north pole and ...

ROYAL SOC CHEMISTRY2019

Gaia Data Release 1 Summary of the astrometric, photometric, and survey properties

Stephan Morgenthaler, Shuangqing Liao

Context. At about 1000 days after the launch of Gaia we present the first Gaia data release, Gaia DR1, consisting of astrometry and photometry for over 1 billion sources brighter than magnitude 20.7. Aims. A summary of Gaia DR1 is presented along with illu ...

EDP Sciences2016

Renormalization and blow up for wave maps from $S^2 \times \mathbb{R}$ to $S^2$

Sohrab Mirshams Shahshahani

We construct a one parameter family of nite time blow ups to the co-rotational wave maps problem from

S^2\times R

S^2

parameterized by

\nu \epsilon (\frac{1}{2},1]

. The longitudinal function

u(t,\alpha)

which is the main object of study will be ...

2016

A deep crust-mantle boundary in the asteroid 4 Vesta

Philippe Gillet, Harold Gabriel Eugène Justin Clenet

The asteroid 4 Vesta was recently found to have two large impact craters near its south pole, exposing subsurface material. Modelling suggested that surface material in the northern hemisphere of Vesta came from a depth of about 20 kilometres, whereas the ...

Nature Publishing Group2014

All-particle cosmic ray energy spectrum measured with 26 IceTop stations

Matthias Wolf, Xiaoxia Bai, Mathieu Ribordy, Shirit Cohen

We report on a measurement of the cosmic ray energy spectrum with the IceTop air shower array, the surface component of the IceCube Neutrino Observatory at the South Pole. The data used in this analysis were taken between June and October, 2007, with 26 su ...

Elsevier Science Bv2013

IceTop: The surface component of IceCube

Matthias Wolf, Xiaoxia Bai, Mathieu Ribordy, Shirit Cohen

IceTop, the surface component of the IceCube Neutrino Observatory at the South Pole, is an air shower array with an area of 1 km(2). The detector allows a detailed exploration of the mass composition of primary cosmic rays in the energy range from about 10 ...

Elsevier Science Bv2013

Observation Of Cosmic-Ray Anisotropy With The Icetop Air Shower Array

Matthias Wolf, Xiaoxia Bai, Mathieu Ribordy, Shirit Cohen

We report on the observation of anisotropy in the arrival direction distribution of cosmic rays at PeV energies. The analysis is based on data taken between 2009 and 2012 with the IceTop air shower array at the south pole. IceTop, an integral part of the I ...

Iop Publishing Ltd2013

OBSERVATION OF ANISOTROPY IN THE GALACTIC COSMIC-RAY ARRIVAL DIRECTIONS AT 400 TeV WITH ICECUBE

Matthias Wolf, Xiaoxia Bai, Mathieu Ribordy, Shirit Cohen

In this paper we report the first observation in the Southern hemisphere of an energy dependence in the Galactic cosmic-ray anisotropy up to a few hundred TeV. This measurement was performed using cosmic-ray-induced muons recorded by the partially deployed ...

2012

Background studies for acoustic neutrino detection at the South Pole

Matthias Wolf, Xiaoxia Bai, Mathieu Ribordy, Shirit Cohen

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

Design and performance of the South Pole Acoustic Test Setup

Mathieu Ribordy

The South Pole Acoustic Test Setup (SPATS) was built to evaluate the acoustic characteristics of the South Pole ice in the 10-100 kHz frequency range, for the purpose of assessing the feasibility of an acoustic neutrino detection array at the South Pole. T ...

2012

Data compression on the sphere

Yves Wiaux, Jason Douglas McEwen

Large data-sets defined on the sphere arise in many fields. In particular, recent and forthcoming observations of the anisotropies of the cosmic microwave background (CMB) made on the celestial sphere contain approximately three and fifty mega-pixels respe ...

Indian Academy of Sciences2011

Calibration and characterization of the IceCube photomultiplier tube

Xiaoxia Bai

Over 5000 PMTs are being deployed at the South Pole to compose the IceCube neutrino observatory. Many are placed deep in the ice to detect Cherenkov light emitted by the products of high-energy neutrino interactions, and others are frozen into tanks on the ...

2010

The IceCube data acquisition system: Signal capture, digitization, and timestamping

Xiaoxia Bai

IceCube is a km-scale neutrino observatory under construction at the South Pole with sensors both in the deep ice (InIce) and on the surface (IceTop). The sensors, called Digital Optical Modules (DOMs). detect, digitize and timestamp the signals from optic ...

2009

Searches For A Diffuse Flux Of Extraterrestrial Muon Neutrinos With The Icecube Observatory

The IceCube observatory is currently being contructed at the South Pole. Scheduled to be completed in 2011, it already offers a large increase in sensitivity over its predecessor, the AMANDA detector. This increase is expected to improve significantly the ...

2009

Non-Gaussianity analysis on local morphological measures of WMAP data

Pierre Vandergheynst, Yves Wiaux

The decomposition of a signal on the sphere with the steerable wavelet constructed from the second Gaussian derivative gives access to the orientation, signed-intensity and elongation of the signal’s local features. In the present work, the non-Gaussianity ...

2008

Alignment and signed-intensity anomalies in WMAP data

Pierre Vandergheynst, Yves Wiaux

Significant alignment and signed-intensity anomalies of local features of the cosmic microwave background (CMB) are detected on the three-year WMAP data, through a decomposition of the signal with steerable wavelets on the sphere. In addition to identifyin ...

2007

Steerable wavelet analysis of CMB structures alignment

Pierre Vandergheynst, Yves Wiaux

This paper reviews the application of a novel methodology for analysing the isotropy of the universe by probing the alignment of local structures in the CMB. The strength of the proposed methodology relies on the steerable wavelet filtering of the CMB sign ...

2006

Publications associées (21)

S^2\times R

S^2

parameterized by

\nu \epsilon (\frac{1}{2},1]

. The longitudinal function

u(t,\alpha)

which is the main object of study will be ...

2016