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Related papers: Numerical study of the cosmic shear

200 papers

An essential aspect of cosmic voids is that these underdense regions provide complementary information about the properties of our Universe. Unlike dense regions, voids are avoided by matter and are less contaminated by baryonic processes.…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-16 Md Rasel Hossen , Sonia Akter Ema , Krzysztof Bolejko , Geraint F. Lewis

We present results of our cosmic shear survey in progress at the Canada- France-Hawaii Telescope (CFHT). We analysed 1.7 sq. degrees of data, out of which we measured a significant correlation of galaxy shape-orientation over several arcmin…

Accelerating expansion of the Universe is a great challenge for both physics and cosmology. In light of lacking the convincing theoretical explanation, an effective description of this phenomenon in terms of cosmic equation of state turns…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 M. Biesiada , A. Piorkowska , B. Malec

Simulating the irradiation of planetary atmospheres by cosmic ray particles requires, among others, the ability to understand and to quantify the interactions of charged particles with planetary magnetic fields. Here we present a process…

Earth and Planetary Astrophysics · Physics 2022-03-14 Jason Hirtz , Ingo Leya

The Cosmological Principle is a cornerstone of the standard model of cosmology and shapes how we view the Universe and our place within it. It is imperative, then, to devise multiple observational tests which can identify and quantify…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-13 James Adam , Roy Maartens , Julien Larena , Chris Clarkson

In this paper we introduce a new observable to measure cosmic shear. We show that if we can measure with good accuracy both, the orientation of a galaxy and the polarisation direction of its radio emission, the angle between them is…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-14 Jérémie Francfort , Giulia Cusin , Ruth Durrer

The abundance of peaks in weak gravitational lensing maps is a potentially powerful cosmological tool, complementary to measurements of the shear power spectrum. We study peaks detected directly in shear maps, rather than convergence maps,…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-16 Nicolas Martinet , James G. Bartlett , Alina Kiessling , Barbara Sartoris

We show that the lensing efficiency of cosmic shear generically has a simple shape, even in the case of a tomographic survey with badly behaved photometric redshifts. We argue that source distributions for cosmic shear can therefore be more…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-21 Nicolas Tessore , Ian Harrison

We examine the cosmological redshift-space distortion effect on the power spectrum of the objects at high-redshifts, which is an unavoidable observational contamination in general relativistic cosmology. In particular, we consider the…

Astrophysics · Physics 2009-10-31 Hiromitsu Magira , Y. P. Jing , Yasushi Suto

We investigate strong gravitational lensing in the concordance $\Lambda$CDM cosmology by carrying out ray-tracing along past light cones through the Millennium Simulation, the largest simulation of cosmic structure formation ever carried…

Astrophysics · Physics 2007-12-03 Stefan Hilbert , Simon D. M. White , Jan Hartlap , Peter Schneider

In cosmic shear likelihood analyses the covariance is most commonly assumed to be constant in parameter space. Therefore, when calculating the covariance matrix (analytically or from simulations), its underlying cosmology should not…

Astrophysics · Physics 2015-05-13 Tim Eifler , Peter Schneider , Jan Hartlap

We derive a new relation between cosological distances, valid in any (statistically) isotropic space-time and independent of cosmological parameters or even the validity of the field equation of General Relativity. In particular, this…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-03 Peter Schneider

Context. Gravitational lensing is one of the leading tools in understanding the dark side of the Universe. The need for accurate, efficient and effective methods which are able to extract this information along with other cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Marika Asgari , Peter Schneider , Patrick Simon

The general idea of determining cosmological parameters with gravitational lensing statistics is outlined, and then recent work---with an emphasis on applicability to all cosmological models, observational bias, better statistics and…

Astrophysics · Physics 2011-04-15 Phillip Helbig

The measurement of large scale anisotropies in cosmic ray arrival directions is generally performed through harmonic analyses of the right ascension distribution as a function of energy. These measurements are challenging due to the small…

Instrumentation and Methods for Astrophysics · Physics 2013-07-29 Olivier Deligny , Francesco Salamida

An important part of cosmological model fitting relies on correlating distance indicators of objects (for example type Ia supernovae) with their redshift, often illustrated on a Hubble diagram. Comparing the observed correlation with a…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-22 Julian Adamek , Chris Clarkson , Louis Coates , Ruth Durrer , Martin Kunz

The distribution of the cosmic convergence field is modeled using a large-deviation principle where all non-Gaussian contributions are computed from first principles. The geometry of the past light cone is accounted for by constructing the…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-22 Alexandre Barthelemy , Sandrine Codis , Cora Uhlemann , Francis Bernardeau , Raphael Gavazzi

Cosmic ray astronomy attempts to identify and study the sources of ultrahigh energy cosmic rays. It is unique in its reliance on charged particles as the information carriers. While no discrete source of ultrahigh energy cosmic rays has…

Astrophysics · Physics 2010-01-15 Paul Sommers , Stefan Westerhoff

We present a Bayesian hierarchical modelling approach to infer the cosmic matter density field, and the lensing and the matter power spectra, from cosmic shear data. This method uses a physical model of cosmic structure formation to infer…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-03 Natalia Porqueres , Alan Heavens , Daniel Mortlock , Guilhem Lavaux
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