中文
相关论文

相关论文: On the insufficiency of arbitrarily precise covari…

200 篇论文

We study the correlations of the shear signal between triplets of sources in the Canada-France-Hawaii Lensing Survey (CFHTLenS) to probe cosmological parameters via the matter bispectrum. In contrast to previous studies, we adopted a…

We present a framework to compute non-Gaussian likelihoods for two-point correlation functions. The non-Gaussianity is most pronounced on large scales that will be well-measured by stage-IV weak-lensing surveys. We show how such a…

宇宙学与河外天体物理 · 物理学 2026-04-09 Veronika Oehl , Tilman Tröster

We study the significance of non-Gaussianity in the likelihood of weak lensing shear two-point correlation functions, detecting significantly non-zero skewness and kurtosis in one-dimensional marginal distributions of shear two-point…

宇宙学与河外天体物理 · 物理学 2020-11-11 Chien-Hao Lin , Joachim Harnois-Déraps , Tim Eifler , Taylor Pospisil , Rachel Mandelbaum , Ann B. Lee , Sukhdeep Singh

The weak lensing power spectrum carries cosmological information via its dependence on the growth of structure and on geometric factors. Since much of the cosmological information comes from scales affected by nonlinear clustering,…

天体物理学 · 物理学 2010-11-02 Masahiro Takada , 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…

We study how well the Gaussian approximation is valid for computing the covariance matrices of the convergence power and bispectrum in weak gravitational lensing analyses. We focus on its impact on the cosmological parameter estimations by…

宇宙学与河外天体物理 · 物理学 2015-06-12 Masanori Sato , Takahiro Nishimichi

We computed the power spectrum of weak cosmic shear in models with non-Gaussian primordial density fluctuations. Cosmological initial conditions deviating from Gaussianity have recently attracted much attention in the literature, especially…

宇宙学与河外天体物理 · 物理学 2015-05-14 C. Fedeli , L. Moscardini

Weak gravitational lensing surveys are rapidly becoming important tools to probe directly the mass density fluctuations in the universe and its background dynamics. Earlier studies have shown that it is possible to model the statistics of…

天体物理学 · 物理学 2009-11-07 Patrick Valageas , Andrew J. Barber , Dipak Munshi

Cosmic shear data contains a large amount of cosmological information encapsulated in the non-Gaussian features of the weak lensing mass maps. This information can be extracted using non-Gaussian statistics. We compare the constraining…

宇宙学与河外天体物理 · 物理学 2021-01-20 Dominik Zürcher , Janis Fluri , Raphael Sgier , Tomasz Kacprzak , Alexandre Refregier

We investigate whether a Gaussian likelihood is sufficient to obtain accurate parameter constraints from a Euclid-like combined tomographic power spectrum analysis of weak lensing, galaxy clustering and their cross-correlation. Testing its…

宇宙学与河外天体物理 · 物理学 2021-03-03 Robin E. Upham , Michael L. Brown , Lee Whittaker

Naive estimates of the statistics of large scale structure and weak lensing power spectrum measurements that include only Gaussian errors exaggerate their scientific impact. Non-linear evolution and finite volume effects are both…

宇宙学与河外天体物理 · 物理学 2014-12-24 Emmanuel Schaan , Masahiro Takada , David N. Spergel

The power spectrum of weak lensing fluctuations has a non-Gaussian distribution due to its quadratic nature. On small scales the Central Limit Theorem acts to Gaussianize this distribution but non-Gaussianity in the signal due to…

宇宙学与河外天体物理 · 物理学 2022-06-29 Alex Hall , Andy Taylor

We study the ability of future weak lensing (WL) surveys to constrain primordial non-Gaussianity of the local type. We use a large ensemble of simulated WL maps with survey specifications relevant to Euclid and LSST. The simulations assume…

宇宙学与河外天体物理 · 物理学 2012-11-05 Stefan Hilbert , Laura Marian , Robert E. Smith , Vincent Desjacques

Weak gravitational lensing has become a common tool to constrain the cosmological model. The majority of the methods to derive constraints on cosmological parameters use second-order statistics of the cosmic shear. Despite their success,…

宇宙学与河外天体物理 · 物理学 2015-06-04 Sandrine Pires , Adrienne Leonard , Jean-Luc Starck

Using 1000 ray-tracing simulations for a {\Lambda}-dominated cold dark model in Sato et al. (2009), we study the covariance matrix of cosmic shear correlation functions, which is the standard statistics used in the previous measurements.…

宇宙学与河外天体物理 · 物理学 2015-05-19 Masanori Sato , Masahiro Takada , Takashi Hamana , Takahiko Matsubara

Upcoming surveys such as \LSST{} and \Euclid{} will significantly improve the power of weak lensing as a cosmological probe. To maximise the information that can be extracted from these surveys, it is important to explore novel statistics…

宇宙学与河外天体物理 · 物理学 2021-08-18 Christopher T. Davies , Marius Cautun , Benjamin Giblin , Baojiu Li , Joachim Harnois-Déraps , Yan-Chuan Cai

Weak gravitational lensing provides a unique method to map directly the dark matter in the Universe. The majority of lensing analyses uses the two-point statistics of the cosmic shear field to constrain the cosmological model yielding…

宇宙学与河外天体物理 · 物理学 2014-11-18 S. Pires , J. -L. Starck , A. Amara , A. Refregier , R. Teyssier

We present exact non-Gaussian joint likelihoods for auto- and cross-correlation functions on arbitrarily masked spherical Gaussian random fields. Our considerations apply to spin-0 as well as spin-2 fields but are demonstrated here for the…

宇宙学与河外天体物理 · 物理学 2025-09-11 Veronika Oehl , Tilman Tröster

Weak gravitational lensing observations probe the spectrum and evolution of density fluctuations and the cosmological parameters which govern them. At low redshifts, the non-linear gravitational evolution of large scale structure produces a…

天体物理学 · 物理学 2009-10-31 Asantha Cooray , Wayne Hu

We study various measures of weak lensing distortions in future surveys, taking into account the noise arising from the finite survey size and the intrinsic ellipticity of galaxies. We also consider a realistic redshift distribution of the…

天体物理学 · 物理学 2009-11-10 Patrick Valageas , Dipak Munshi , Andrew J. Barber
‹ 上一页 1 2 3 10 下一页 ›