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We present a new Unbiased Minimal Variance (UMV) estimator for the purpose of reconstructing the large--scale structure of the universe from noisy, sparse and incomplete data. Similar to the Wiener Filter (WF), the UMV estimator is derived…

Astrophysics · Physics 2009-10-31 Saleem Zaroubi

We undertake the first comprehensive and quantitative real-space analysis of the cosmological information content in the environments of the cosmic web (voids, filaments, walls, and nodes) up to non-linear scales, $k = 0.5$ $h$/Mpc. Relying…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-25 Tony Bonnaire , Nabila Aghanim , Joseph Kuruvilla , Aurélien Decelle

This paper introduces a novel lightweight computational framework for enhancing images under low-light conditions, utilizing advanced machine learning and convolutional neural networks (CNNs). Traditional enhancement techniques often fail…

Computer Vision and Pattern Recognition · Computer Science 2024-05-22 Zhuoheng Li , Yuheng Pan , Houcheng Yu , Zhiheng Zhang

We construct two new summary statistics, the scale-dependent peak height function (scale-PKHF) and the scale-dependent valley depth function (scale-VLYDF) of matter density, and forecast their constraining power on primordial…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-06 Yun Wang , Ping He

It was recently shown that neural networks can be combined with the analytic method of scale-dependent bias to obtain a measurement of local primordial non-Gaussianity, which is optimal in the squeezed limit that dominates the…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-03 Yurii Kvasiuk , Moritz Münchmeyer , Kendrick Smith

The form of the primordial power spectrum has the potential to differentiate strongly between competing models of perturbation generation in the early universe and so is of considerable importance. The recent release of five years of WMAP…

Astrophysics · Physics 2015-05-13 M. Bridges , F. Feroz , M. P. Hobson , A. N. Lasenby

We present the strongest robust constraints on primordial non-Gaussianity (PNG) from currently available galaxy surveys, combining large-scale clustering measurements and their cross-correlations with the cosmic microwave background. We…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-22 Tommaso Giannantonio , Ashley J. Ross , Will J. Percival , Robert Crittenden , David Bacher , Martin Kilbinger , Robert Nichol , Jochen Weller

We consider estimation of a deterministic unknown parameter vector in a linear model with non-Gaussian noise. In the Gaussian case, dimensionality reduction via a linear matched filter provides a simple low dimensional sufficient statistic…

Applications · Statistics 2013-11-05 Jakob Vovnoboy , Ami Wiesel

Dark matter cannot be observed directly, but its weak gravitational lensing slightly distorts the apparent shapes of background galaxies, making weak lensing one of the most promising probes of cosmology. Several observational studies have…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-18 Dezső Ribli , Bálint Ármin Pataki , István Csabai

We study signatures of primordial non-Gaussianity (PNG) in the redshift-space halo field on non-linear scales, using a combination of three summary statistics, namely the halo mass function (HMF), power spectrum, and bispectrum. The choice…

Fast and accurate simulations of the non-linear evolution of the cosmic density field are a major component of many cosmological analyses, but the computational time and storage required to run them can be exceedingly large. For this…

Cosmology and Nongalactic Astrophysics · Physics 2020-11-17 Richard M. Feder , Philippe Berger , George Stein

We study the statistical inference of the cosmological dark matter density field from non-Gaussian, non-linear and non-Poisson biased distributed tracers. We have implemented a Bayesian posterior sampling computer-code solving this problem…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-01 Metin Ata , Francisco-Shu Kitaura , Volker Müller

Spacecraft pose estimation plays a vital role in many on-orbit space missions, such as rendezvous and docking, debris removal, and on-orbit maintenance. At present, space images contain widely varying lighting conditions, high contrast and…

Computer Vision and Pattern Recognition · Computer Science 2023-09-08 Hu Gao , Zhihui Li , Depeng Dang , Ning Wang , Jingfan Yang

We study the limits of accuracy for weak lensing maps of dark matter using diffuse 21-cm radiation from the pre-reionization epoch using simulations. We improve on previous "optimal" quadratic lensing estimators by using shear and…

Astrophysics · Physics 2009-11-13 Tingting Lu , Ue-Li Pen

The goal of this paper is to present a non-iterative and more importantly an extremely fast algorithm to reconstruct images from compressively sensed (CS) random measurements. To this end, we propose a novel convolutional neural network…

Computer Vision and Pattern Recognition · Computer Science 2016-03-09 Kuldeep Kulkarni , Suhas Lohit , Pavan Turaga , Ronan Kerviche , Amit Ashok

Ongoing and planned weak lensing (WL) surveys are becoming deep enough to contain information on angular scales down to a few arcmin. To fully extract information from these small scales, we must capture non-Gaussian features in the…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-09 Tianhuan Lu , Zoltán Haiman , José Manuel Zorrilla Matilla

We investigate the effect of non-Gaussianity on the reconstruction of the initial mass field from the Ly$\alpha$ forest. We show that the transmitted flux of QSO absorption spectra are highly non-Gaussian in terms of the statistics, the…

Astrophysics · Physics 2009-10-31 Long-Long Feng , Li-Zhi Fang

Detecting and measuring a non-Gaussian signature of primordial origin in the density field is a major science goal of next-generation galaxy surveys. The signal will permit us to determine primordial physics processes and constrain models…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-15 Adam Andrews , Jens Jasche , Guilhem Lavaux , Fabian Schmidt

We develop a hybrid GNN-CNN architecture for the reconstruction of 3-dimensional continuous cosmological matter fields from discrete point clouds, provided by observed galaxy catalogs. Using the CAMELS hydrodynamical cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-06 Yurii Kvasiuk , Jordan Krywonos , Matthew C. Johnson , Moritz Münchmeyer

After an artificial model background subtraction, the pixels have been labelled as foreground and background. Previous approaches to secondary processing the output for denoising usually use traditional methods such as the Bayesian…

Computer Vision and Pattern Recognition · Computer Science 2021-03-30 Ningbo Zhu , Fei Yang
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