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Low-dose CT images are essential for reducing radiation exposure in cancer screening, pediatric imaging, and longitudinal monitoring protocols, but their quality is often degraded by noise from low-dose acquisition, patient motion, or…

Computer Vision and Pattern Recognition · Computer Science 2026-03-12 Jitindra Fartiyal , Pedro Freire , Sergei K. Turitsyn , Sergei G. Solovski

The cosmic 21-cm line of hydrogen is expected to be measured in detail by the next generation of radio telescopes. The enormous dataset from future 21-cm surveys will revolutionize our understanding of early cosmic times. We present a…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-11 Sudipta Sikder , Rennan Barkana , Itamar Reis , Anastasia Fialkov

We apply Bayesian statistics to perform model selection on different reionisation scenarios via the Multinest algorithm. Initially, we recover the results shown by 21CMMC for the parameter estimation of 21cmFAST models. We proceed to test…

Instrumentation and Methods for Astrophysics · Physics 2019-05-15 T. Binnie , J. R. Pritchard

Detecting redshifted 21cm emission from neutral hydrogen in the early Universe promises to give direct constraints on the epoch of reionization (EoR). It will, though, be very challenging to extract the cosmological signal (CS) from…

Diffusion models (DMs) have rapidly emerged as a powerful framework for image generation and restoration. However, existing DMs are primarily trained in a supervised manner by using a large corpus of clean images. This reliance on clean…

Image and Video Processing · Electrical Eng. & Systems 2025-10-15 Brett Levac , Jon Tamir , Marcelo Pereyra , Julian Tachella

The amplitude of redshifted 21 cm fluctuations during the Epoch of Reionization (EoR) is expected to show a distinctive "rise and fall" behavior with decreasing redshift as reionization proceeds. On large scales (k <~ 0.1 Mpc^{-1}) this can…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-06 Angus Beane , Adam Lidz

We explore likelihood-free (aka simulation-based) Bayesian model selection to quantify model comparison analyses of reionisation scenarios. We iteratively train the 3D Convolutional Neural Network (CNN) on four toy EoR models based on…

Instrumentation and Methods for Astrophysics · Physics 2025-02-13 T. Binnie , Xiaosheng Zhao , J. R. Pritchard , Yi Mao

Noise reduction techniques based on deep learning have demonstrated impressive performance in enhancing the overall quality of recorded speech. While these approaches are highly performant, their application in audio engineering can be…

Sound · Computer Science 2023-10-18 Christian J. Steinmetz , Thomas Walther , Joshua D. Reiss

Speckle noise poses a significant challenge in maintaining the quality of synthetic aperture radar (SAR) images, so SAR despeckling techniques have drawn increasing attention. Despite the tremendous advancements of deep learning in…

Computer Vision and Pattern Recognition · Computer Science 2024-01-09 Xuran Hu , Ziqiang Xu , Zhihan Chen , Zhengpeng Feng , Mingzhe Zhu , LJubisa Stankovic

Cross-correlations between 21cm observations and galaxy surveys provide a powerful probe of reionization by reducing foreground sensitivity while linking ionization morphology to galaxies. We quantify the constraining power of 21cm-Galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-27 Yannic Pietschke , Anne Hutter , Caroline Heneka

We study the reknown deconvolution problem of recovering a distribution function from independent replicates (signal) additively contaminated with random errors (noise), whose distribution is known. We investigate whether a Bayesian…

Statistics Theory · Mathematics 2021-11-15 Judith Rousseau , Catia Scricciolo

We introduce a powerful semi-numeric modeling tool, 21cmFAST, designed to efficiently simulate the cosmological 21-cm signal. Our code generates 3D realizations of evolved density, ionization, peculiar velocity, and spin temperature fields,…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Andrei Mesinger , Steven Furlanetto , Renyue Cen

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

We explore the impact of dark matter annihilation on the 21-cm signal during the cosmic dawn and epoch of reionization (EoR). Using modified 21cmFAST simulations and convolutional neural networks (CNNs), we investigate how energy injected…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-10 Atsushi J. Nishizawa , Pravin Kumar Natwariya , Kenji Kadota

Considerable observational efforts are being dedicated to measuring the sky-averaged (global) 21-cm signal of neutral hydrogen from Cosmic Dawn and the Epoch of Reionization. Deriving observational constraints on the astrophysics of this…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-18 Christian H. Bye , Stephen K. N. Portillo , Anastasia Fialkov

The 21-cm PDF (i.e., distribution of pixel brightness temperatures) is expected to be highly non-Gaussian during reionization and to provide important information on the distribution of density and ionization. We measure the 21-cm PDF as a…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Kazuhide Ichikawa , Rennan Barkana , Ilian T. Iliev , Garrelt Mellema , Paul Shapiro

Predicting the 21cm signal from the epoch of reionization and cosmic dawn is a complex and challenging task. Various simplifying assumptions have been applied over the last decades to make the modeling more affordable. In this paper, we…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-25 Timothée Schaeffer , Sambit K. Giri , Aurel Schneider

Transformer-based diffusion models have demonstrated remarkable performance at generating high-quality samples. However, our theoretical understanding of the reasons for this success remains limited. For instance, existing models are…

Machine Learning · Computer Science 2026-04-14 Hongkang Li , Hancheng Min , Rene Vidal

The observed 21-cm signal from the epoch of reionization will be distorted along the line-of-sight by the peculiar velocities of matter particles. These redshift-space distortions will affect the contrast in the signal and will also make it…

The rapid evolution of the cosmological neutral hydrogen (HI) distribution during the EoR is imprinted along the line of sight (LoS) in the redshifted 21-cm signal due to the light cone (LC) effect. The LC EoR 21-cm signal ceases to be…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-06 Suman Pramanick , Somnath Bharadwaj , Khandakar Md Asif Elahi , Rajesh Mondal
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