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Related papers: Sample variance in weak lensing: how many simulati…

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In order to reach the required performance of Stage-III and IV weak lensing surveys, cosmic shear measurements have to rely on external simulations to calibrate residual biases. Over the years, several techniques have been developed to…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-11 G. Congedo , A. N. Taylor

We study the impact of systematic errors on planned weak lensing surveys and compute the requirements on their contributions so that they are not a dominant source of the cosmological parameter error budget. The generic types of error we…

Astrophysics · Physics 2010-04-06 Dragan Huterer , Masahiro Takada , Gary Bernstein , Bhuvnesh Jain

The results from weak gravitational lensing analyses are subject to a cosmic variance error term that has previously been estimated assuming Gaussian statistics. In this letter we address the issue of estimating cosmic variance errors for…

Focusing on the well motivated aperture mass statistics $\Map$, we study the possibility of constraining cosmological parameters using future space based SNAP class weak lensing missions. Using completely analytical results we construct the…

Astrophysics · Physics 2007-05-23 Dipak Munshi , Patrick Valageas

In the very near future, weak lensing surveys will map the projected density of the universe in an unbiased way over large regions of the sky. In order to interpret the results of studies it is helpful to develop an understanding of the…

Astrophysics · Physics 2008-11-26 Dipak Munshi , Peter Coles

Measurements of the shear induced by weak gravitational lensing around galaxy cluster lines of sight are the gold standard for calibrating cluster observable-mass relations, thereby enabling a robust and precise inference of cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-26 S. Bocquet , A. Fumagalli , C. T. Davies , K. Dolag , S. Grandis , J. J. Mohr

We investigate weak lensing by large-scale structure using ray tracing through N-body simulations. Photon trajectories are followed through high resolution simulations of structure formation to make simulated maps of shear and convergence…

Astrophysics · Physics 2009-09-25 Bhuvnesh Jain , Uros Seljak , Simon White

Galactic sized gravitational lenses are simulated by combining a cosmological N-body simulation and models for the baryonic component of the galaxy. The lens caustics, critical curves, image locations and magnification ratios are calculated…

Astrophysics · Physics 2009-11-10 Adam Amara , R. Benton Metcalf , Thomas J. Cox , Jeremiah P. Ostriker

We investigate the accuracy of weak lensing simulations by comparing the results of five independently developed lensing simulation codes run on the same input $N$-body simulation. Our comparison focuses on the lensing convergence maps…

We estimate the impact of weak lensing by strongly nonlinear cosmological structures on the cosmic microwave background. Accurate calculation of large $\ell$ multipoles requires N-body simulations and ray-tracing schemes with both high…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 M. J. Fullana , J. V. Arnau , R. J. Thacker , H. M. P. Couchman , D. Sáez

We model weak gravitational lensing of light by large-scale structure using ray tracing through N-body simulations. The method is described with particular attention paid to numerical convergence. We investigate some of the key…

Astrophysics · Physics 2008-11-26 Chris Vale , Martin White

We develop a method for estimating the shear power spectra from weak lensing observations and test it on simulated data. Our method describes the shear field in terms of angular power spectra and cross correlation of the two shear modes…

Astrophysics · Physics 2008-11-26 Wayne Hu , Martin White

We present a survey of the cosmological applications of the next generation of weak lensing surveys, paying special attention to the computational challenges presented by the number of galaxies, $N_{gal} ~$ 10$^{5}$. We focus on optimal…

Astrophysics · Physics 2009-11-07 N. Padmanabhan , U. Seljak , U. L. Pen

Upcoming weak lensing surveys will survey large cosmological volumes to measure the growth of cosmological structure with time and thereby constrain dark energy. One major systematic uncertainty in this process is the calibration of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Arun Kannawadi , Rachel Mandelbaum , Claire Lackner

We present a concept study on weak lensing map reconstruction through the cosmic magnification effect in galaxy number density distribution. We propose a minimal variance linear estimator to minimize both the dominant systematical and…

Cosmology and Nongalactic Astrophysics · Physics 2012-02-16 Xinjuan Yang , Pengjie Zhang

The weak lensing shear signal has been measured numerically in $N$-body simulations at 14 different redshifts ($z_s = 0.1$ to 3.6) and on angular scales of $\theta = 2'$ to 32'. In addition, the data have been validated by analytical…

Astrophysics · Physics 2009-11-07 Andrew J. Barber

Extracting parameter constraints from cosmological observations requires accurate determination of the covariance matrix for use in the likelihood function. We show here that uncertainties in the elements of the covariance matrix propagate…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-30 Scott Dodelson , Michael D. Schneider

Cosmological weak lensing by the large scale structure of the Universe, cosmic shear, is coming of age as a powerful probe of the parameters describing the cosmological model and matter power spectrum. It complements CMB studies, by…

Astrophysics · Physics 2009-11-10 Patrick Simon , Lindsay J. King , Peter Schneider

The B modes generated by the lensing of CMB polarization are a primary target for the upcoming generation of experiments and can potentially constrain quantities such as the neutrino mass and dark energy equation of state. The net sample…

Astrophysics · Physics 2011-05-12 Kendrick M. Smith , Wayne Hu , Manoj Kaplinghat

We present a cosmic shear analysis of the 100 square degree weak lensing survey, combining data from the CFHTLS-Wide, RCS, VIRMOS-DESCART and GaBoDS surveys. Spanning ~100 square degrees, with a median source redshift z~0.78, this combined…