Institution
Institute of Cosmology and Gravitation, University of Portsmouth
About: Institute of Cosmology and Gravitation, University of Portsmouth is a based out in . It is known for research contribution in the topics: Galaxy & Redshift. The organization has 297 authors who have published 1207 publications receiving 76919 citations.
Topics: Galaxy, Redshift, Dark energy, Dark matter, Cosmic microwave background
Papers published on a yearly basis
Papers
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University of Wyoming1, Ohio State University2, University of Utah3, University of Paris4, Max Planck Society5, University of La Laguna6, Spanish National Research Council7, Durham University8, University of Washington9, Institute of Cosmology and Gravitation, University of Portsmouth10, Sternberg Astronomical Institute11, New Mexico State University12, Pennsylvania State University13, Harvard University14, National Autonomous University of Mexico15, University of Pittsburgh16, Perimeter Institute for Theoretical Physics17, University of Waterloo18, Institut d'Astrophysique de Paris19, Sejong University20, Indian Institute of Astrophysics21
TL;DR: In this article, the authors present the final Sloan Digital Sky Survey IV (SDSS-IV) quasar catalog from Data Release 16 of the extended Baryon Oscillation Spectroscopic Survey (eBOSS).
Abstract: We present the final Sloan Digital Sky Survey IV (SDSS-IV) quasar catalog from Data Release 16 of the extended Baryon Oscillation Spectroscopic Survey (eBOSS). This catalog comprises the largest selection of spectroscopically confirmed quasars to date. The full catalog includes two subcatalogs (the current versions are DR16Q_v4 and DR16Q_Superset_v3 at https://data.sdss.org/sas/dr16/eboss/qso/DR16Q/): a "superset" of all SDSS-IV/eBOSS objects targeted as quasars containing 1,440,615 observations and a quasar-only catalog containing 750,414 quasars, including 225,082 new quasars appearing in an SDSS data release for the first time, as well as known quasars from SDSS-I/II/III. We present automated identification and redshift information for these quasars alongside data from visual inspections for 320,161 spectra. The quasar-only catalog is estimated to be 99.8% complete with 0.3%–1.3% contamination. Automated and visual inspection redshifts are supplemented by redshifts derived via principal component analysis and emission lines. We include emission-line redshifts for Hα, Hβ, Mg ii, C iii], C iv, and Lyα. Identification and key characteristics generated by automated algorithms are presented for 99,856 broad absorption-line quasars and 35,686 damped Lyman alpha quasars. In addition to SDSS photometric data, we also present multiwavelength data for quasars from the Galaxy Evolution Explorer, UKIDSS, the Wide-field Infrared Survey Explorer, FIRST, ROSAT/2RXS, XMM-Newton, and Gaia. Calibrated digital optical spectra for these quasars can be obtained from the SDSS Science Archive Server.
167 citations
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TL;DR: In this paper, the authors study cosmological constraints on metric f(R) gravity models that are designed to reproduce the LCDM expansion history with modifications to gravity described by a supplementary cosmology freedom, the Compton wavelength parameter B_0.
Abstract: We study cosmological constraints on metric f(R) gravity models that are designed to reproduce the LCDM expansion history with modifications to gravity described by a supplementary cosmological freedom, the Compton wavelength parameter B_0. We conduct a Markov chain Monte Carlo analysis on the parameter space, utilizing the geometrical constraints from supernovae distances, the baryon acoustic oscillation distances, and the Hubble constant, along with all of the cosmic microwave background data, including the largest scales, its correlation with galaxies, and a probe of the relation between weak gravitational lensing and galaxy flows. The strongest constraints, however, are obtained through the inclusion of data from cluster abundance. Using all of the data, we infer a bound of B_0<0.0011 at the 95% C.L.
166 citations
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TL;DR: In this paper, an extension of Hořava-Lifshitz gravity was proposed in order to address the pathological behavior of the scalar mode all previous versions of the theory exhibit.
165 citations
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Alain Blanchard1, Stefano Camera2, Carmelita Carbone3, Carmelita Carbone4 +173 more•Institutions (50)
TL;DR: In this paper, the authors present validated Euclid cosmological forecasts for galaxy clustering, weak lensing, and the combination thereof, which combine both theoretical and observational ingredients for different Cosmological probes.
Abstract: Aims. The Euclid space telescope will measure the shapes and redshifts of galaxies to reconstruct the expansion history of the Universe and the growth of cosmic structures. The estimation of the expected performance of the experiment, in terms of predicted constraints on cosmological parameters, has so far relied on various individual methodologies and numerical implementations, which were developed for different observational probes and for the combination thereof. In this paper we present validated forecasts, which combine both theoretical and observational ingredients for different cosmological probes. This work is presented to provide the community with reliable numerical codes and methods for Euclid cosmological forecasts.Methods. We describe in detail the methods adopted for Fisher matrix forecasts, which were applied to galaxy clustering, weak lensing, and the combination thereof. We estimated the required accuracy for Euclid forecasts and outline a methodology for their development. We then compare and improve different numerical implementations, reaching uncertainties on the errors of cosmological parameters that are less than the required precision in all cases. Furthermore, we provide details on the validated implementations, some of which are made publicly available, in different programming languages, together with a reference training-set of input and output matrices for a set of specific models. These can be used by the reader to validate their own implementations if required.Results. We present new cosmological forecasts for Euclid . We find that results depend on the specific cosmological model and remaining freedom in each setting, for example flat or non-flat spatial cosmologies, or different cuts at non-linear scales. The numerical implementations are now reliable for these settings. We present the results for an optimistic and a pessimistic choice for these types of settings. We demonstrate that the impact of cross-correlations is particularly relevant for models beyond a cosmological constant and may allow us to increase the dark energy figure of merit by at least a factor of three.
165 citations
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TL;DR: In this paper, the stability of the Einstein static universe was analyzed by considering homogeneous scalar perturbations in the context of f(R) modified theories of gravity, and the stability regions of the solutions were parametrized by a linear equation of state parameter w=p/{rho.
Abstract: We analyze the stability of the Einstein static universe by considering homogeneous scalar perturbations in the context of f(R) modified theories of gravity. By considering specific forms of f(R), the stability regions of the solutions are parametrized by a linear equation of state parameter w=p/{rho}. Contrary to classical general relativity, it is found that in f(R) gravity a stable Einstein cosmos with a positive cosmological constant does indeed exist. Thus, we are lead to conclude that, in principle, modifications in f(R) gravity stabilize solutions which are unstable in general relativity.
165 citations
Authors
Showing all 297 results
Name | H-index | Papers | Citations |
---|---|---|---|
Robert C. Nichol | 187 | 851 | 162994 |
Daniel Thomas | 134 | 846 | 84224 |
Will J. Percival | 129 | 473 | 87752 |
Tommaso Treu | 126 | 715 | 49090 |
Claudia Maraston | 103 | 362 | 59178 |
Marco Cavaglia | 93 | 372 | 60157 |
Ashley J. Ross | 90 | 248 | 46395 |
David A. Wake | 89 | 214 | 46124 |
László Á. Gergely | 89 | 426 | 60674 |
L. K. Nuttall | 89 | 253 | 54834 |
Rita Tojeiro | 87 | 229 | 43140 |
Roy Maartens | 86 | 432 | 23747 |
David Keitel | 85 | 253 | 56849 |
Davide Pietrobon | 83 | 152 | 62010 |
Gong-Bo Zhao | 81 | 287 | 35540 |