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Related papers: De-noising non-Gaussian fields in cosmology with n…

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We make use of recent results from random matrix theory to identify a derived threshold, for isolating noise from image features. The procedure assumes the existence of a set of noisy images, where denoising can be carried out on individual…

Data Analysis, Statistics and Probability · Physics 2010-04-09 Gaurab Basu , Kaushik Ray , Prasanta K. Panigrahi

Removing the shape noise from the observed weak lensing field, i.e., denoising, enhances the potential of WL by accessing information at small scales where the shape noise dominates without denoising. We utilise two machine learning (ML)…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-13 Shohei D. Aoyama , Ken Osato , Masato Shirasaki

This letter presents a new approach using the cosmic peculiar velocity field to characterize the morphology and size of large scale structures in the local Universe. The algorithm developed uses the three-dimensional peculiar velocity field…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-31 A. Dupuy , H. M. Courtois , F. Dupont , F. Denis , R. Graziani , Y. Copin , D. Pomarede , N. Libeskind , E. Carlesi , B. Tully , D. Guinet

The Fourier transformation is an effective and efficient operation of Gaussianization at the one-point level. Using a set of N-body simulation data, we verified that the one-point distribution functions of the dark matter momentum…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-05 Ming Li , Jun Pan , Pengjie Zhang , Jie Wang , Longlong Feng , Liang Gao , Xi Kang , Guoliang Li , Weipeng Lin , Haihui Wang

Diffusion models generate high-quality synthetic data. They operate by defining a continuous-time forward process which gradually adds Gaussian noise to data until fully corrupted. The corresponding reverse process progressively "denoises"…

We study Minkowski Functionals as probes of primordial non-Gaussianity in the Cosmic Microwave Background, specifically for the estimate of the primordial `local' bi-spectrum parameter f_NL, with instrumental parameters which should be…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Anne Ducout , François Bouchet , Stéphane Colombi , Dmitri Pogosyan , Simon Prunet

We prove an exact relationship between the optimal denoising function and the data distribution in the case of additive Gaussian noise, showing that denoising implicitly models the structure of data allowing it to be exploited in the…

Neural and Evolutionary Computing · Computer Science 2017-09-11 Heikki Arponen , Matti Herranen , Harri Valpola

Cosmological fine-tuning has traditionally been associated with the narrowness of the intervals in which the parameters of the physical models must be located to make life possible. A more thorough approach focuses on the probability of the…

History and Philosophy of Physics · Physics 2022-04-26 Daniel Andrés Díaz-Pachón , Ola Hössjer , Robert J. Marks

Denoising diffusion models have recently shown impressive results in generative tasks. By learning powerful priors from huge collections of training images, such models are able to gradually modify complete noise to a clean natural image…

Computer Vision and Pattern Recognition · Computer Science 2023-06-29 Naama Pearl , Yaron Brodsky , Dana Berman , Assaf Zomet , Alex Rav Acha , Daniel Cohen-Or , Dani Lischinski

For faster sampling and higher sample quality, we propose DiNof ($\textbf{Di}$ffusion with $\textbf{No}$rmalizing $\textbf{f}$low priors), a technique that makes use of normalizing flows and diffusion models. We use normalizing flows to…

Computer Vision and Pattern Recognition · Computer Science 2025-03-25 Mohsen Zand , Ali Etemad , Michael Greenspan

Blood flow imaging provides important information for hemodynamic behavior within the vascular system and plays an essential role in medical diagnosis and treatment planning. However, obtaining high-quality flow images remains a significant…

Numerical Analysis · Mathematics 2026-04-02 Han Zhang , Xue-Cheng Tai , Jean-Michel Morel , Raymond H. Chan

Phase retrieval is the nonlinear inverse problem of recovering a true signal from its Fourier magnitude measurements. It arises in many applications such as astronomical imaging, X-Ray crystallography, microscopy, and more. The problem is…

Computer Vision and Pattern Recognition · Computer Science 2023-05-11 Rohun Agrawal , Oscar Leong

We extend field-level inference to jointly constrain the cosmological parameters $\{A,\omega_{\rm cdm},H_0\}$, in both real and redshift space. Our analyses are based on mock data generated using a perturbative forward model, with noise…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-25 Kazuyuki Akitsu , Marko Simonović , Shi-Fan Chen , Giovanni Cabass , Matias Zaldarriaga

To enhance low-light images to normally-exposed ones is highly ill-posed, namely that the mapping relationship between them is one-to-many. Previous works based on the pixel-wise reconstruction losses and deterministic processes fail to…

Image and Video Processing · Electrical Eng. & Systems 2021-09-14 Yufei Wang , Renjie Wan , Wenhan Yang , Haoliang Li , Lap-Pui Chau , Alex C. Kot

Astronomical images are essential for exploring and understanding the universe. Optical telescopes capable of deep observations, such as the Hubble Space Telescope, are heavily oversubscribed in the Astronomical Community. Images also often…

Instrumentation and Methods for Astrophysics · Physics 2020-11-25 Antonia Vojtekova , Maggie Lieu , Ivan Valtchanov , Bruno Altieri , Lyndsay Old , Qifeng Chen , Filip Hroch

Knowledge of the primordial matter density field from which the large-scale structure of the Universe emerged over cosmic time is of fundamental importance for cosmology. However, reconstructing these cosmological initial conditions from…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-06 Oleg Savchenko , Guillermo Franco Abellán , Florian List , Noemi Anau Montel , Christoph Weniger

The distribution of the cosmic convergence field is modeled using a large-deviation principle where all non-Gaussian contributions are computed from first principles. The geometry of the past light cone is accounted for by constructing the…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-22 Alexandre Barthelemy , Sandrine Codis , Cora Uhlemann , Francis Bernardeau , Raphael Gavazzi

We numerically investigate non-Gaussianities in the late-time cosmological density field in Fourier space. We explore various statistics, including the two-point and three-point probability distribution function (PDF) of phase and modulus,…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-14 Jian Qin , Jun Pan , Yu Yu , Pengjie Zhang

Cosmography is a model-independent phenomenological approach to observational cosmology, relying on Taylor series expansions of physical quantities as a function of the cosmological redshift or other analogous variables. A recent work…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-27 C. J. A. P. Martins

Fluorescence microscopy has enabled a dramatic development in modern biology. Due to its inherently weak signal, fluorescence microscopy is not only much noisier than photography, but also presented with Poisson-Gaussian noise where Poisson…

Computer Vision and Pattern Recognition · Computer Science 2019-04-09 Yide Zhang , Yinhao Zhu , Evan Nichols , Qingfei Wang , Siyuan Zhang , Cody Smith , Scott Howard