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Related papers: Estimating the Integrated Bispectrum from Weak Len…

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We introduce two kurt-spectra to probe fourth-order statistics of weak lensing convergence maps. Using state-of-the-art numerical simulations, we study the shapes of these kurt-spectra as a function of source redshifts and smoothing angular…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-16 Dipak Munshi , Hayden Lee , Cora Dvorkin , Jason D. McEwen

We consider the problem of learning a sparse graph underlying an undirected Gaussian graphical model, a key problem in statistical machine learning. Given $n$ samples from a multivariate Gaussian distribution with $p$ variables, the goal is…

Machine Learning · Computer Science 2026-04-07 Kayhan Behdin , Wenyu Chen , Rahul Mazumder

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

We compute the weak lensing convergence power spectrum, $C^{\kappa\kappa}(\theta)$, in a dust-filled universe using fully non-linear general relativistic simulations. The spectrum is then compared to more standard, approximate calculations…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-29 John T. Giblin , James B. Mertens , Glenn D. Starkman , Andrew R. Zentner

Based on realistic simulations, we propose an hybrid method to reconstruct the lensing potential power spectrum, directly on PLANCK-like CMB frequency maps. It implies using a large galactic mask and dealing with a strong inhomogeneous…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-20 S. Plaszczynski , A. Lavabre , L. Perotto , J. -L. Starck

We compute the matter bispectrum in the presence of primordial local non-Gaussianity over a wide range of scales, including the very small nonlinear ones. We use the Halo Model approach, considering non-Gaussian corrections to the halo…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 D. G. Figueroa , E. Sefusatti , A. Riotto , F. Vernizzi

We present the first halo model based description of the Cosmic Infrared Background (CIB) non-Gaussianity (NG) that is fully parametric. To this end, we introduce, for the first time, a diagrammatic method to compute high order polyspectra…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-05 Fabien Lacasa , Aurélie Pénin , Nabila Aghanim

Intrinsically aligned galaxy shapes are one of the most important systematics in cosmic shear measurements. So far theoretical studies of intrinsic alignments almost exclusively focus on their statistics at the two-point level. Results from…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Philipp M. Merkel , Bjoern Malte Schaefer

We investigate gravitational lensing by \textit{special} Buchdahl inspired metric with the Buchdahl parameter $\tilde{k}$. In strong deflection limit, we derive the deflection angle analytically for the light rays that diverge as photons…

General Relativity and Quantum Cosmology · Physics 2025-01-08 Shafia Maryam , Mubasher Jamil , Mustapha Azreg-Aïnou , Zoe C S Chan

Modified Gravity theories generally affect the Poisson equation and the gravitational slip (effective anisotropic stress) in an observable way, that can be parameterized by two generic functions ($\eta$ and $\mu$) of time and space. We bin…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-06 Santiago Casas , Martin Kunz , Matteo Martinelli , Valeria Pettorino

Extreme-mass-ratio-inspiral observations from future space-based gravitational-wave detectors such as LISA will enable strong-field tests of general relativity with unprecedented precision, but at prohibitive computational cost if existing…

General Relativity and Quantum Cosmology · Physics 2018-06-07 Alvin J. K. Chua , Sonke Hee , Will J. Handley , Edward Higson , Christopher J. Moore , Jonathan R. Gair , Michael P. Hobson , Anthony N. Lasenby

We investigate spherically symmetric, static spacetimes in Eddington-inspired Born-Infeld gravity coupled to Born-Infeld electrodynamics. The two constants, $b^2$ and $\kappa$ which parametrise the Born-Infeld structures in the…

General Relativity and Quantum Cosmology · Physics 2015-10-06 Soumya Jana , Sayan Kar

Hu [Phys. Rev. D62 (2000) 043007] has presented a harmonic-space method for calculating the effects of weak gravitational lensing on the cosmic microwave background (CMB) over the full sky. Computing the lensed power spectra to first order…

Astrophysics · Physics 2009-11-07 Anthony Challinor , Gayoung Chon

(Abridged) Weak gravitational lensing induces distortions on the images of background galaxies, and thus provides a direct measure of mass fluctuations in the universe. Since the distortions induced by lensing on the images of background…

Astrophysics · Physics 2009-10-31 David Bacon , Alexandre Refregier , Douglas Clowe , Richard Ellis

In this paper, we propose a novel Bayesian approach for nonparametric estimation in Wicksell's problem. This has important applications in astronomy for estimating the distribution of the positions of the stars in a galaxy given projected…

Statistics Theory · Mathematics 2025-09-01 Francesco Gili , Geurt Jongbloed , Aad van der Vaart

We present projected constraints on modified gravity models from the observational technique known as 21 cm intensity mapping, where cosmic structure is detected without resolving individual galaxies. The resulting map is sensitive to both…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-06 Kiyoshi Wesley Masui , Fabian Schmidt , Ue-Li Pen , Patrick McDonald

We study perturbations of 4-dimensional fuzzy spheres as backgrounds in the IKKT or IIB matrix model. Gauge fields and metric fluctuations are identified among the excitation modes with lowest spin, supplemented by a tower of higher-spin…

High Energy Physics - Theory · Physics 2017-02-28 Harold C. Steinacker

Using infrared spectroscopy, we investigate bottom gated ABA-stacked trilayer graphene subject to an additional environment-induced p-type doping. We find that the Slonczewski-Weiss-McClure tight-binding model and the Kubo formula reproduce…

Mesoscale and Nanoscale Physics · Physics 2012-12-27 N. Ubrig , P. Blake , D. van der Marel , A. B. Kuzmenko

We identify universal signatures in the bispectrum arising from a transient tachyonic instability of entropic fluctuations during inflation, a phenomenon that naturally arises in hyperbolic field-space geometries. We perform exact numerical…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-02 Shuntaro Aoki , Diederik Roest , Denis Werth

We combine wide and deep galaxy number-count data from GAMA, COSMOS/G10, HST ERS, HST UVUDF and various near-, mid- and far- IR datasets from ESO, Spitzer and Herschel. The combined data range from the far-UV (0.15microns) to far-IR…