Author
Elisabetta Majerotto
Other affiliations: Institute of Cosmology and Gravitation, University of Portsmouth, INAF, Autonomous University of Madrid
Bio: Elisabetta Majerotto is an academic researcher from University of Geneva. The author has contributed to research in topics: Dark energy & Dark matter. The author has an hindex of 19, co-authored 26 publications receiving 4667 citations. Previous affiliations of Elisabetta Majerotto include Institute of Cosmology and Gravitation, University of Portsmouth & INAF.
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TL;DR: Euclid as mentioned in this paper is a space-based survey mission from the European Space Agency designed to understand the origin of the universe's accelerating expansion, using cosmological probes to investigate the nature of dark energy, dark matter and gravity by tracking their observational signatures.
Abstract: Euclid is a space-based survey mission from the European Space Agency designed to understand the origin of the Universe's accelerating expansion. It will use cosmological probes to investigate the nature of dark energy, dark matter and gravity by tracking their observational signatures on the geometry of the universe and on the cosmic history of structure formation. The mission is optimised for two independent primary cosmological probes: Weak gravitational Lensing (WL) and Baryonic Acoustic Oscillations (BAO). The Euclid payload consists of a 1.2 m Korsch telescope designed to provide a large field of view. It carries two instruments with a common field-of-view of ~0.54 deg2: the visual imager (VIS) and the near infrared instrument (NISP) which contains a slitless spectrometer and a three bands photometer. The Euclid wide survey will cover 15,000 deg2 of the extragalactic sky and is complemented by two 20 deg2 deep fields. For WL, Euclid measures the shapes of 30-40 resolved galaxies per arcmin2 in one broad visible R+I+Z band (550-920 nm). The photometric redshifts for these galaxies reach a precision of dz/(1+z) \lt 0.05. They are derived from three additional Euclid NIR bands (Y, J, H in the range 0.92-2.0 micron), complemented by ground based photometry in visible bands derived from public data or through engaged collaborations. The BAO are determined from a spectroscopic survey with a redshift accuracy dz/(1+z) =0.001. The slitless spectrometer, with spectral resolution ~250, predominantly detects Ha emission line galaxies. Euclid is a Medium Class mission of the ESA Cosmic Vision 2015-2025 programme, with a foreseen launch date in 2019. This report (also known as the Euclid Red Book) describes the outcome of the Phase A study.
1,213 citations
Heidelberg University1, Korea Institute for Advanced Study2, University of Nottingham3, Institute of Cosmology and Gravitation, University of Portsmouth4, University of Oxford5, INAF6, Istituto Nazionale di Fisica Nucleare7, University of Bologna8, University of Padua9, University of Toulouse10, University of Geneva11, University of Trieste12, Roma Tre University13, University of Milan14, Federal University of Rio Grande do Norte15, University of Oslo16, University College London17, Imperial College London18, Ludwig Maximilian University of Munich19, Autonomous University of Madrid20, ETH Zurich21, University of Edinburgh22, Leiden University23, Sun Yat-sen University24, Max Planck Society25, Royal Institute of Technology26, University of Milano-Bicocca27, University of California, Berkeley28, University of Pennsylvania29, Universidade Federal do Espírito Santo30, University of Porto31, University of Portsmouth32, King's College London33, Durham University34, Institut d'Astrophysique de Paris35, Helsinki Institute of Physics36, University of Lisbon37, Paris Diderot University38, Université Paris-Saclay39, University of Surrey40, University of Trento41, University of Chile42, Academy of Sciences of the Czech Republic43, University of Cyprus44, University of Barcelona45, California Institute of Technology46, Perimeter Institute for Theoretical Physics47
TL;DR: Euclid is a European Space Agency medium-class mission selected for launch in 2020 within the cosmic vision 2015-2025 program as discussed by the authors, which will explore the expansion history of the universe and the evolution of cosmic structures by measuring shapes and red-shift of galaxies as well as the distribution of clusters of galaxies over a large fraction of the sky.
Abstract: Euclid is a European Space Agency medium-class mission selected for launch in 2020 within the cosmic vision 2015–2025 program. The main goal of Euclid is to understand the origin of the accelerated expansion of the universe. Euclid will explore the expansion history of the universe and the evolution of cosmic structures by measuring shapes and red-shifts of galaxies as well as the distribution of clusters of galaxies over a large fraction of the sky. Although the main driver for Euclid is the nature of dark energy, Euclid science covers a vast range of topics, from cosmology to galaxy evolution to planetary research. In this review we focus on cosmology and fundamental physics, with a strong emphasis on science beyond the current standard models. We discuss five broad topics: dark energy and modified gravity, dark matter, initial conditions, basic assumptions and questions of methodology in the data analysis. This review has been planned and carried out within Euclid’s Theory Working Group and is meant to provide a guide to the scientific themes that will underlie the activity of the group during the preparation of the Euclid mission.
1,211 citations
14 Oct 2011
TL;DR: Euclid as discussed by the authors is a space-based survey mission from the European Space Agency designed to understand the origin of the universe's accelerating expansion, using cosmological probes to investigate the nature of dark energy, dark matter and gravity by tracking their observational signatures.
Abstract: Euclid is a space-based survey mission from the European Space Agency designed to understand the origin of the Universe's accelerating expansion. It will use cosmological probes to investigate the nature of dark energy, dark matter and gravity by tracking their observational signatures on the geometry of the universe and on the cosmic history of structure formation. The mission is optimised for two independent primary cosmological probes: Weak gravitational Lensing (WL) and Baryonic Acoustic Oscillations (BAO). The Euclid payload consists of a 1.2 m Korsch telescope designed to provide a large field of view. It carries two instruments with a common field-of-view of ~0.54 deg2: the visual imager (VIS) and the near infrared instrument (NISP) which contains a slitless spectrometer and a three bands photometer. The Euclid wide survey will cover 15,000 deg2 of the extragalactic sky and is complemented by two 20 deg2 deep fields. For WL, Euclid measures the shapes of 30-40 resolved galaxies per arcmin2 in one broad visible R+I+Z band (550-920 nm). The photometric redshifts for these galaxies reach a precision of dz/(1+z) < 0.05. They are derived from three additional Euclid NIR bands (Y, J, H in the range 0.92-2.0 micron), complemented by ground based photometry in visible bands derived from public data or through engaged collaborations. The BAO are determined from a spectroscopic survey with a redshift accuracy dz/(1+z) =0.001. The slitless spectrometer, with spectral resolution ~250, predominantly detects Ha emission line galaxies. Euclid is a Medium Class mission of the ESA Cosmic Vision 2015-2025 programme, with a foreseen launch date in 2019. This report (also known as the Euclid Red Book) describes the outcome of the Phase A study.
1,189 citations
TL;DR: In this article, the authors consider the case where the dark energy is modelled as a fluid with constant equation of state parameter w and show that the combination of constant w and a simple interaction with dark matter leads to an instability in the dark sector perturbations at early times: the curvature perturbation blows up on super-Hubble scales.
Abstract: If dark energy interacts with dark matter, this gives a new approach to the coincidence problem. But interacting dark energy models can suffer from pathologies. We consider the case where the dark energy is modelled as a fluid with constant equation of state parameter w. Non-interacting constant-w models are well behaved in the background and in the perturbed universe. But the combination of constant w and a simple interaction with dark matter leads to an instability in the dark sector perturbations at early times: the curvature perturbation blows up on super-Hubble scales. Our results underline how important it is to carefully analyse the relativistic perturbations when considering models of coupled dark energy. The instability that we find has been missed in some previous work where the perturbations were not consistently treated. The unstable mode dominates even if adiabatic initial conditions are used. The instability also arises regardless of how weak the coupling is. This non-adiabatic instability is different from previously discovered adiabatic instabilities on small scales in the strong-coupling regime.
294 citations
TL;DR: The Dvali-Gabadadze-Porrati (DGP) braneworld model provides a simple alternative to the standard lambda cold dark matter cosmology, with the same number of parameters.
Abstract: The Dvali-Gabadadze-Porrati (DGP) braneworld model provides a simple alternative to the standard lambda cold dark matter cosmology, with the same number of parameters. There is no dark energy---the late universe self-accelerates due to an infrared modification of gravity. We compute the joint constraints on the DGP model from supernovae, the cosmic microwave background shift parameter, and the baryon oscillation peak in the Sloan Digital Sky Survey luminous red galaxy sample. Flat DGP models are within the joint 2 sigma contour, but the lambda cold dark matter model provides a significantly better fit to the data. These tests are based on the background dynamics of the DGP model, and we comment on further tests that involve structure formation.
181 citations
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TL;DR: In this paper, a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) is presented.
Abstract: Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These
9,929 citations
TL;DR: A comprehensive survey of recent work on modified theories of gravity and their cosmological consequences can be found in this article, where the authors provide a reference tool for researchers and students in cosmology and gravitational physics, as well as a selfcontained, comprehensive and up-to-date introduction to the subject as a whole.
3,674 citations
[...]
TL;DR: Various applications of f(R) theories to cosmology and gravity — such as inflation, dark energy, local gravity constraints, cosmological perturbations, and spherically symmetric solutions in weak and strong gravitational backgrounds are reviewed.
Abstract: Over the past decade, f(R) theories have been extensively studied as one of the simplest modifications to General Relativity. In this article we review various applications of f(R) theories to cosmology and gravity - such as inflation, dark energy, local gravity constraints, cosmological perturbations, and spherically symmetric solutions in weak and strong gravitational backgrounds. We present a number of ways to distinguish those theories from General Relativity observationally and experimentally. We also discuss the extension to other modified gravity theories such as Brans-Dicke theory and Gauss-Bonnet gravity, and address models that can satisfy both cosmological and local gravity constraints.
3,375 citations
University of Chicago1, Lawrence Berkeley National Laboratory2, Pierre-and-Marie-Curie University3, University of Pennsylvania4, Argonne National Laboratory5, Fermilab6, University of Cape Town7, African Institute for Mathematical Sciences8, Texas A&M University9, University of Portsmouth10, University of Cambridge11, University of Toronto12, Wayne State University13, University of Colorado Boulder14, University of Tokyo15, California Institute of Technology16, University of Victoria17, University of California, Berkeley18, University of Illinois at Urbana–Champaign19, University of Chile20, Autonomous University of Barcelona21, Stockholm University22, University of Texas at Austin23, Princeton University24, University of Oxford25, Las Cumbres Observatory Global Telescope Network26, University of California, Santa Barbara27, Rutgers University28, University of Copenhagen29, Australian Astronomical Observatory30, Instituto Superior Técnico31, University of Utah32, Rochester Institute of Technology33, Johns Hopkins University34, Space Telescope Science Institute35, Pennsylvania State University36, University of the Western Cape37, University of Southampton38
TL;DR: In this article, the authors presented cosmological constraints from a joint analysis of type Ia supernova (SN Ia) observations obtained by the SDSS-II and SNLS collaborations.
Abstract: Aims. We present cosmological constraints from a joint analysis of type Ia supernova (SN Ia) observations obtained by the SDSS-II and SNLS collaborations. The dataset includes several low-redshift samples (z< 0.1), all three seasons from the SDSS-II (0.05
1,939 citations
TL;DR: In this article, the authors present extensive forecasts for constraints on the dark energy equation of state and parameterized deviations from General Relativity, achievable with Stage III and Stage IV experimental programs that incorporate supernovae, BAO, weak lensing, and cosmic microwave background data.
1,253 citations