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Related papers: Quasar Lensing Statistics and Omega_Lambda: What W…

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We perform a combined likelihood analysis of the latest cosmic microwave background anisotropy data and distant Type 1a Supernova data of Perlmutter etal (1998a). Our analysis is restricted to cosmological models where structure forms from…

Astrophysics · Physics 2009-10-31 G. Efstathiou , S. L. Bridle A. N. Lasenby , M. P. Hobson , R. S. Ellis

Measurements of the Hubble constant, and more generally measurements of the expansion rate and distances over the interval $0 < z < 1$, appear to be inconsistent with the predictions of the standard cosmological model ($\Lambda$CDM) given…

Cosmology and Nongalactic Astrophysics · Physics 2020-03-04 Lloyd Knox , Marius Millea

We investigate the origin of $\Lambda$CDM parameter constraints in weak lensing, with a focus on the Hubble constant. We explain why current cosmic shear data are sensitive to the parameter combination $S_8 \propto \sigma_8 \Omega_m^{0.5}$,…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-30 Alex Hall

Time-Delay Cosmography is a technique for measuring $H_0$ with strong gravitational lensing. It requires a correction for line of sight perturbations, and it is necessary to build tools to assess populations of these lines of sight…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-04 Patrick R. Wells , Christopher D. Fassnacht , Simon Birrer , Devon Williams

We present constraints on the cosmological constant $\lambda_{0}$ from gravitational lensing statistics of the Jodrell Bank-VLA Astrometric Survey (JVAS). Although this is the largest gravitational lens survey which has been analysed,…

Astrophysics · Physics 2009-10-31 P. Helbig , D. R. Marlow , R. Quast , P. N. Wilkinson , I. W. A. Browne , L. V. E. Koopmans

We use Cosmic Microwave Background (CMB) observations together with the Red-sequence Cluster Survey (RCS) weak lensing results to derive constraints on a range of cosmological parameters. This particular choice of observations is motivated…

Astrophysics · Physics 2008-11-26 Carlo R. Contaldi , Henk Hoekstra , Antony Lewis

The matter content of the Universe is strongly inhomogeneous on small scales. Motivated by this fact, we consider a model of the Universe that has regularly spaced discrete masses, rather than a continuous fluid. The optical properties of…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Timothy Clifton , Pedro G. Ferreira

By comparing the results of numerical microlensing simulations to the observed long-term variability of quasars, strong upper limits on the cosmological density of compact objects in the mass range 0.01 to 0.0001 solar masses may be…

Astrophysics · Physics 2009-11-07 E. Zackrisson , N. Bergvall , P. Helbig

Strong lensing time-delay systems constrain cosmological parameters via the so-called time-delay distance and the angular diameter distance to the lens. In previous studies, only the former information was used. In this paper, we show that…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-27 Inh Jee , Eiichiro Komatsu , Sherry H. Suyu , Dragan Huterer

Via the magnification bias, gravitational lensing by large-scale structures causes angular cross-correlations between distant quasars and foreground galaxies on angular scales of arc minutes and above. We investigate the three-point…

Astrophysics · Physics 2007-05-23 Brice Menard , Matthias Bartelmann , Yannick Mellier

The goal of the present paper is to assess the usefulness of quasars as cosmological distance indicators. We calibrate, in a model-independent way, the non-linear relation between X-ray and UV emission to derive quasar luminosity distances.…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-12 Ariadna Montiel , Sofia Samario-Nava , Juan Carlos Hidalgo , Jose Ignacio Cabrera

We report measurements of the mass density, Omega_M, and cosmological-constant energy density, Omega_Lambda, of the universe based on the analysis of 42 Type Ia supernovae discovered by the Supernova Cosmology Project. The…

The precision of Cosmic Microwave Background (CMB) experiments, specifically its lensing reconstruction, has reached the limit where non-linear corrections cannot be ignored. Neglecting these corrections results in biased constraints on…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-27 Cynthia Trendafilova , Ali Rida Khalife , Silvia Galli

We use current observations on the number statistics of gravitationally lensed optical arcs towards galaxy clusters to derive an upper limit on the cosmological mass density of the Universe. The gravitational lensing statistics due to…

Astrophysics · Physics 2009-10-31 Asantha R. Cooray

Observations of the Cosmic Microwave Background (CMB), large scale structure (LSS) and standard candles such as Type 1a Supernovae (SN) each place different constraints on the values of cosmological parameters. We assume an inflationary…

Astrophysics · Physics 2007-05-23 A. N. Lasenby , S. L. Bridle , M. P. Hobson

We cross-correlate the positions of damped Lyman-$\alpha$ systems (DLAs) and their parent quasar catalog with a convergence map derived from the Planck cosmic microwave background (CMB) temperature data. We make consistent measurements of…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-27 David Alonso , Joseph Colosimo , Andreu Font-Ribera , Anže Slosar

I review the major concordances and controversies of the meeting concerning observations. Cosmologists are nearing agreement on the global cosmological parameters of the Universe. A few parameters still have large error bars, notably…

Astrophysics · Physics 2009-09-29 S. M. Faber

The cosmic curvature, a fundamental parameter for cosmology could hold deep clues to inflation and cosmic origins. We propose an improved model-independent method to constrain the cosmic curvature by combining the constructed Hubble diagram…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-19 Tonghua Liu , Shuo Cao , Jia Zhang , Marek Biesiada , Yuting Liu , Yujie Lian

We compare and combine likelihood functions of the cosmological parameters Omega_m, h and sigma_8 from the CMB, type Ia supernovae and from probes of large scale structure. We include the recent results from the CMB experiments BOOMERANG…

Astrophysics · Physics 2007-05-23 S. L. Bridle