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We present a new method for delensing $B$ modes of the cosmic microwave background (CMB) using a lensing potential reconstructed from the same realization of the CMB polarization (CMB internal delensing). The $B$-mode delensing is required…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-31 Toshiya Namikawa

Cosmological inhomogeneities gravitationally deflect radiation propagating from distant sources, transforming the spatial and angular correlation functions of intrinsic source properties. For a gaussian distribution of deflections (e.g.…

Astrophysics · Physics 2007-05-23 Eric V. Linder

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…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Masanori Sato , Takahiro Nishimichi

Gravitational lensing distorts the cosmic microwave background (CMB) anisotropies and imprints a characteristic pattern onto it. The distortions depend on the projected matter density between today and redshift $z \sim 1100$. In this paper…

Astrophysics · Physics 2016-08-25 Matias Zaldarriaga , Uros Seljak

We discuss the four-point correlation function, or the trispectrum in Fourier space, of CMB temperature and polarization anisotropies due to the weak gravitational lensing effect by intervening large scale structure. We discuss the squared…

Astrophysics · Physics 2009-11-07 Asantha Cooray , Michael Kesden

Deep surveys of the CMB polarization have more information on the lensing signal than the quadratic estimators (QE) can capture. We showed in a recent work that a CMB lensing power spectrum built from a single optimized CMB lensing mass…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-15 Louis Legrand , Julien Carron

Local non-Gaussianity causes correlations between large scale perturbation modes and the small scale power. The large-scale CMB signal has contributions from the integrated Sachs Wolfe (ISW) effect, which does not correlate with the small…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-02 James M. G. Mead , Antony Lewis , Lindsay J. King

In the last few decades, advances in observational cosmology have given us a standard model of cosmology. We know the content of the universe to within a few percent. With more ambitious experiments on the way, we hope to move beyond the…

Cosmology and Nongalactic Astrophysics · Physics 2011-09-26 Amit P. S. Yadav , Benjamin D. Wandelt

Upcoming cosmic microwave background (CMB) lensing measurements and tomographic galaxy surveys are expected to provide us with high-precision data sets in the coming years, thus paving the way for fruitful cross-correlation analyses. In…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-27 Priyesh Chakraborty , Shu-Fan Chen , Cora Dvorkin

We investigate whether a Gaussian likelihood, as routinely assumed in the analysis of cosmological data, is supported by simulated survey data. We define test statistics, based on a novel method that first destroys Gaussian correlations in…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-15 Elena Sellentin , Alan F. Heavens

Weak gravitational lensing induces flux dependent fluctuations in the observed galaxy number density distribution. This cosmic magnification (magnification bias) effect in principle enables lensing reconstruction alternative to cosmic shear…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-04 Ruijie Ma , Pengjie Zhang , Yu Yu , Jian Qin

We investigate the noncommutative effect on the non-Gaussianities of primordial cosmological perturbation. In the lowest order of string length and slow-roll parameter, we find that in the models with small speed of sound the noncommutative…

Astrophysics · Physics 2008-12-18 Kejie Fang , Bin Chen , Wei Xue

Weak gravitational lensing by intervening large-scale structure induces a distinct signature in the cosmic microwave background (CMB) that can be used to reconstruct the weak-lensing displacement map. Estimators for individual Fourier modes…

Astrophysics · Physics 2016-08-30 Michael Kesden , Asantha Cooray , Marc Kamionkowski

Our view of the last-scattering surface in the cosmic microwave background (CMB) is obscured by secondary anisotropies, sourced by scattering, extragalactic emission and gravitational processes between recombination and observation. Whilst…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-10 William Coulton , Alexander Miranthis , Anthony Challinor

We forecast combined future constraints from the cosmic microwave background and large-scale structure on the models of primordial non-Gaussianity. We study the generalized local model of non-Gaussianity, where the parameter f_NL is…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Adam Becker , Dragan Huterer , Kenji Kadota

We investigate the relative sensitivities of several tests for deviations from Gaussianity in the primordial distribution of density perturbations. We consider models for non-Gaussianity that mimic that which comes from inflation as well as…

Astrophysics · Physics 2009-10-31 Licia Verde , Raul Jimenez , Marc Kamionkowski , Sabino Matarrese

Large scale structure deflects cosmic microwave background (CMB) photons. Since large angular scales in the large scale structure contribute significantly to the gravitational lensing effect, a realistic simulation of CMB lensing requires a…

Astrophysics · Physics 2009-11-13 Sudeep Das , Paul Bode

It is known that the Cosmic Microwave Background (CMB) temperature fluctuations are modified by gravitational lensing since the angular positions of photons are altered by the metric perturbations. We reconsider this effect in the context…

General Relativity and Quantum Cosmology · Physics 2021-02-03 Ali Kaya

While the $\Lambda$CDM model succeeds on large scales, its validity on smaller scales remains uncertain. Recent works suggest that non-halo dark matter structures, such as filaments and walls, could significantly influence gravitational…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-21 Baptiste Jego , Giulia Despali , Tamara Richardson , Jens Stücker

The current weak lensing measurements of the large scale structure are mostly related to statistical study of background galaxy ellipticities. We consider a possibility to extend lensing studies with intrinsically unresolved sources and…

Astrophysics · Physics 2008-11-26 Asantha Cooray