Institution
IFAE
Other•Barcelona, Spain•
About: IFAE is a other organization based out in Barcelona, Spain. It is known for research contribution in the topics: Large Hadron Collider & Galaxy. The organization has 664 authors who have published 1270 publications receiving 51097 citations. The organization is also known as: Instituto de Fisica de Altas Energias & IFAE.
Topics: Large Hadron Collider, Galaxy, Higgs boson, Redshift, MAGIC (telescope)
Papers published on a yearly basis
Papers
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Paris Diderot University1, Ludwig Maximilian University of Munich2, Max Planck Society3, INAF4, University of Porto5, IFAE6, Centre National D'Etudes Spatiales7, University of Edinburgh8, University of Geneva9, Spanish National Research Council10, Aix-Marseille University11, University of Zurich12, University of Oslo13, University of Bonn14, Durham University15, École Polytechnique16, California Institute of Technology17, University of Bologna18, Complutense University of Madrid19, University of Lisbon20, Universidad Politécnica de Cartagena21
TL;DR: In this article, two mass-inversion methods, the Kaiser and Squires method (KS) and the mass-mapping systematic effects (KS+), were proposed to reduce the information loss during the mass inversion.
Abstract: Weak lensing, which is the deflection of light by matter along the line of sight, has proven to be an efficient method for constraining models of structure formation and reveal the nature of dark energy. So far, most weak-lensing studies have focused on the shear field that can be measured directly from the ellipticity of background galaxies. However, within the context of forthcoming full-sky weak-lensing surveys such as Euclid, convergence maps (mass maps) offer an important advantage over shear fields in terms of cosmological exploitation. While it carry the same information, the lensing signal is more compressed in the convergence maps than in the shear field. This simplifies otherwise computationally expensive analyses, for instance, non-Gaussianity studies. However, the inversion of the non-local shear field requires accurate control of systematic effects caused by holes in the data field, field borders, shape noise, and the fact that the shear is not a direct observable (reduced shear). We present the two mass-inversion methods that are included in the official Euclid data-processing pipeline: the standard Kaiser & Squires method (KS), and a new mass-inversion method (KS+) that aims to reduce the information loss during the mass inversion. This new method is based on the KS method and includes corrections for mass-mapping systematic effects. The results of the KS+ method are compared to the original implementation of the KS method in its simplest form, using the Euclid Flagship mock galaxy catalogue. In particular, we estimate the quality of the reconstruction by comparing the two-point correlation functions and third- and fourth-order moments obtained from shear and convergence maps, and we analyse each systematic effect independently and simultaneously. We show that the KS+ method substantially reduces the errors on the two-point correlation function and moments compared to the KS method. In particular, we show that the errors introduced by the mass inversion on the two-point correlation of the convergence maps are reduced by a factor of about 5, while the errors on the third- and fourth-order moments are reduced by factors of about 2 and 10, respectively.
13 citations
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University of Queensland1, Lawrence Berkeley National Laboratory2, University of Pennsylvania3, University of Chicago4, Australian National University5, University of Portsmouth6, University of Southampton7, Stanford University8, University of Illinois at Urbana–Champaign9, Fermilab10, Institut d'Astrophysique de Paris11, University College London12, IFAE13, Texas A&M University14, Spanish National Research Council15, Autonomous University of Madrid16, University of Michigan17, ETH Zurich18, University of California, Santa Cruz19, Ohio State University20, University of Arizona21, Macquarie University22, University of São Paulo23, California Institute of Technology24, Brandeis University25, State University of Campinas26, Oak Ridge National Laboratory27, Argonne National Laboratory28
TL;DR: In this article, a new Bayesian hierarchical model (BHM) named Steve was proposed for performing Type Ia supernova (SN Ia) cosmology fits, which improved the treatment of Malmquist bias, accounting for additional sources of systematic uncertainty and increasing numerical efficiency.
Abstract: We present a new Bayesian hierarchical model (BHM) named Steve for performing Type Ia supernova (SN Ia) cosmology fits. This advances previous works by including an improved treatment of Malmquist bias, accounting for additional sources of systematic uncertainty, and increasing numerical efficiency. Given light-curve fit parameters, redshifts, and host-galaxy masses, we fit Steve simultaneously for parameters describing cosmology, SN Ia populations, and systematic uncertainties. Selection effects are characterized using Monte Carlo simulations. We demonstrate its implementation by fitting realizations of SN Ia data sets where the SN Ia model closely follows that used in Steve. Next, we validate on more realistic SNANA simulations of SN Ia samples from the Dark Energy Survey and low-redshift surveys (DES Collaboration et al. 2018). These simulated data sets contain more than 60,000 SNe Ia, which we use to evaluate biases in the recovery of cosmological parameters, specifically the equation of state of dark energy, w. This is the most rigorous test of a BHM method applied to SN Ia cosmology fitting and reveals small w biases that depend on the simulated SN Ia properties, in particular the intrinsic SN Ia scatter model. This w bias is less than 0.03 on average, less than half the statistical uncertainty on w. These simulation test results are a concern for BHM cosmology fitting applications on large upcoming surveys; therefore, future development will focus on minimizing the sensitivity of Steve to the SN Ia intrinsic scatter model.
13 citations
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TL;DR: In this article, a search for new phenomena in events characterised by high jet multiplicity, no leptons (electrons or muons), and four or more jets originating from the fragmentation of b-quarks (b-jets) is presented.
Abstract: A search is presented for new phenomena in events characterised by high jet multiplicity, no leptons (electrons or muons), and four or more jets originating from the fragmentation of b-quarks (b-jets). The search uses $139~\hbox {fb}^{-1}$ of $\sqrt{s}$ = 13 TeV proton–proton collision data collected by the ATLAS experiment at the Large Hadron Collider during Run 2. The dominant Standard Model background originates from multijet production and is estimated using a data-driven technique based on an extrapolation from events with low b-jet multiplicity to the high b-jet multiplicities used in the search. No significant excess over the Standard Model expectation is observed and 95% confidence-level limits that constrain simplified models of R-parity-violating supersymmetry are determined. The exclusion limits reach 950 GeV in top-squark mass in the models considered.
13 citations
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TL;DR: In this article, the first results from very high-energy observations of the dwarf spheroidal satellite candidate Triangulum II with the MAGIC telescopes from 62.4h of good-quality data taken between August 2016 and August 2017 were presented.
13 citations
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TL;DR: In this article, the authors proposed a method to find the optimal set of features for each node in a set of images, which can be found under doi:10.1140/epjc/s10052-015-3726-9
Abstract: The online version of the original article can be found under doi:10.1140/epjc/s10052-015-3726-9
13 citations
Authors
Showing all 672 results
Name | H-index | Papers | Citations |
---|---|---|---|
J. S. Lange | 160 | 2083 | 145919 |
Diego F. Torres | 137 | 948 | 72180 |
M. I. Martínez | 134 | 1251 | 79885 |
Jose Flix | 133 | 1257 | 90626 |
Matteo Cavalli-Sforza | 129 | 1273 | 89442 |
Ilya Korolkov | 128 | 884 | 75312 |
Martine Bosman | 128 | 942 | 73848 |
Maria Pilar Casado | 128 | 981 | 78550 |
Clement Helsens | 128 | 870 | 74899 |
Imma Riu | 128 | 954 | 73842 |
Sebastian Grinstein | 128 | 1222 | 79158 |
Remi Zaidan | 126 | 744 | 71647 |
Arely Cortes-Gonzalez | 124 | 774 | 68755 |
Trisha Farooque | 124 | 841 | 69620 |
Martin Tripiana | 124 | 716 | 69652 |