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How much can we know about our Universe? All of our observations are restricted to a finite volume, and therefore our estimates of presumably global cosmological parameters are necessarily based on incomplete information. Even assuming that…

Astrophysics · Physics 2008-04-11 T. P. Waterhouse , J. P. Zibin

Likelihood fitting to two-point clustering statistics made from galaxy surveys usually assumes a multivariate normal distribution for the measurements, with justification based on the central limit theorem given the large number of…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-23 Mike Shengbo Wang , Will J. Percival , Santiago Avila , Robert Crittenden , Davide Bianchi

We test the effects of varying the cosmological parameter values used in the strong lens modeling process for the six Hubble Frontier Fields (HFF) galaxy clusters. The standard procedure for generating high fidelity strong lens models…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-27 Matthew B. Bayliss , Keren Sharon , Traci Johnson

Despite the assumption that an ideal FLRW observer is not dependent on the local environment, observations are biased by the positions of the observers due to the matter correlations in the large-scale structure (LSS) of the universe. The…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-26 Sonia Akter Ema , Md Rasel Hossen , Krzysztof Bolejko , Geraint F. Lewis

Cosmic shear is the distortion of images of distant galaxies due to weak gravitational lensing by the large-scale structure in the Universe. Such images are coherently deformed by the tidal field of matter inhomogeneities along the line of…

Cosmology and Nongalactic Astrophysics · Physics 2015-07-22 Martin Kilbinger

We use available measurements to estimate the unknown parameters (variance, smoothness parameter, and covariance length) of a covariance function by maximizing the joint Gaussian log-likelihood function. To overcome cubic complexity in the…

Computation · Statistics 2018-09-13 Alexander Litvinenko , Ying Sun , Marc G. Genton , David Keyes

Recently, a new framework for describing the multiverse has been proposed which is based on the principles of quantum mechanics. The framework allows for well-defined predictions, both regarding global properties of the universe and…

High Energy Physics - Theory · Physics 2013-05-29 Grant Larsen , Yasunori Nomura , H. L. L. Roberts

The averaging problem in cosmology is of considerable importance for the correct interpretation of cosmological data. A rigorous mathematical definition of averaging in a cosmological model is necessary. In general, a spacetime is…

General Relativity and Quantum Cosmology · Physics 2010-12-06 A. A. Coley

We present a field-based approach to the analysis of cosmic shear data to infer jointly cosmological parameters and the dark matter distribution. This forward modelling approach samples the cosmological parameters and the initial matter…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-17 Natalia Porqueres , Alan Heavens , Daniel Mortlock , Guilhem Lavaux

Significant adjustments to the values of the cosmological parameters estimated from high-redshift Type Ia Supernov\ae data are reported, almost an order of magnitude greater than previously found. They arise from the effects of weak…

Astrophysics · Physics 2009-10-31 Andrew J. Barber

Weak gravitational lensing causes subtle changes in the apparent shapes of galaxies due to the bending of light by the gravity of foreground masses. By measuring the shapes of large numbers of galaxies (millions in recent surveys, up to…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-08 Yuki Okura , Andrea Petri , Morgan May , Andrés A. Plazas , Toru Tamagawa

We develop a general formalism for analysing parameter information from non-Gaussian cosmic fields. The method can be adapted to include the nonlinear effects in galaxy redshift surveys, weak lensing surveys and cosmic velocity field…

Astrophysics · Physics 2009-10-31 Andy Taylor , Peter Watts

Upcoming surveys will map the growth of large-scale structure with unprecented precision, improving our understanding of the dark sector of the Universe. Unfortunately, much of the cosmological information is encoded by the small scales,…

Validating modeling choices through simulated analyses and quantifying the impact of different systematic effects will form a major computational bottleneck in the preparation for 3$\times$2 analysis with Stage-IV surveys such as Vera Rubin…

It is well-known that allowing for spatial curvature affects constraints on cosmological parameters such as the dark energy equation of state parameters. Here we study the effect of curvature on constraints on parameters used to test…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Jason Dossett , Mustapha Ishak

In this brief paper we revisit the Fisher information content of cosmological power spectra or two-point functions of Gaussian fields in order to comment on the assumption of Gaussian estimators and the use of parameter-dependent covariance…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-19 Julien Carron

Weak gravitational lensing provides a unique method to map directly the distribution of dark matter in the universe and to measure cosmological parameters. This cosmic-shear technique is based on the measurement of the weak distortions that…

Astrophysics · Physics 2008-11-26 Alexandre Refregier

Weak lensing of galaxies by large scale structure can potentially measure cosmological quantities as accurately as the cosmic microwave background (CMB). However, the relation between observables and fundamental parameters is more complex…

Astrophysics · Physics 2009-10-31 Wayne Hu , Max Tegmark

It is known that modeling uncertainties and astrophysical foregrounds can potentially introduce appreciable bias in the deduced values of cosmological parameters. While it is commonly assumed that these uncertainties will be accounted for…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Meir Shimon , Nissan Itzhaki , Yoel Rephaeli

We apply two Bayesian hierarchical inference schemes to infer shear power spectra, shear maps and cosmological parameters from the CFHTLenS weak lensing survey - the first application of this method to data. In the first approach, we sample…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-10 Justin Alsing , Alan F. Heavens , Andrew H. Jaffe
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