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This survey is devoted to recent developments in the statistical analysis of spherical data, with a view to applications in Cosmology. We will start from a brief discussion of Cosmological questions and motivations, arguing that most…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-28 Javier Carrón Duque , Domenico Marinucci

We explore the reconstruction of the gravitational lensing field of the cosmic microwave background in real space showing that very little statistical information is lost when estimators of short range on the celestial sphere are used in…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Martin Bucher , Carla Sofia Carvalho , Kavilan Moodley , Mathieu Remazeilles

Here we introduce the Delaunay Density Estimator Method. Its purpose is rendering a fully volume-covering reconstruction of a density field from a set of discrete data points sampling this field. Reconstructing density or intensity fields…

Astrophysics · Physics 2007-05-23 W. E. Schaap , R. van de Weygaert

The decomposition of an image into a linear combination of digitised basis functions is an everyday task in astronomy. A general method is presented for performing such a decomposition optimally into an arbitrary set of digitised basis…

Astrophysics · Physics 2009-11-10 R. H. Berry , M. P. Hobson , S. Withington

State of the art methods in astronomical image reconstruction rely on the resolution of a regularized or constrained optimization problem. Solving this problem can be computationally intensive and usually leads to a quadratic or at least…

Computer Vision and Pattern Recognition · Computer Science 2017-06-08 Rémi Flamary

A new method for improving the resolution of astronomical images is presented. It is based on the principle that sampled data cannot be fully deconvolved without violating the sampling theorem. Thus, the sampled image should not be…

Astrophysics · Physics 2009-10-30 P. Magain , F. Courbin , S. Sohy

From the nature of dark matter to the rate of expansion of our Universe, observations of distant galaxies distorted through strong gravitational lensing have the potential to answer some of the major open questions in astrophysics. Modeling…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-18 Siddharth Mishra-Sharma , Ge Yang

Integral field spectroscopy can map astronomical objects spatially and spectroscopically. Due to instrumental and atmospheric effects, it is common for integral field instruments to yield a sampling of the sky image that is both irregular…

Astrophysics of Galaxies · Physics 2020-01-08 Dou Liu , Michael R. Blanton , David R. Law

Geometric reconstruction of opaque surfaces from images is a longstanding challenge in computer vision, with renewed interest from volumetric view synthesis algorithms using radiance fields. We leverage the geometry field proposed in recent…

Graphics · Computer Science 2025-03-31 Kaiwen Jiang , Venkataram Sivaram , Cheng Peng , Ravi Ramamoorthi

The reconstruction of the CMBR power spectrum from a map represents a major computational challenge to which much effort has been applied. However, once the power spectrum has been recovered there still remains the problem of extracting…

Astrophysics · Physics 2009-12-30 Steen Hannestad

Reconstructing astrophysical and cosmological fields from observations is challenging. It requires accounting for non-linear transformations, mixing of spatial structure, and noise. In contrast, forward simulators that map fields to…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-01 Florian List , Noemi Anau Montel , Christoph Weniger

Radio-astronomical observations are increasingly contaminated by interference, and suppression techniques become essential. A powerful candidate for interference mitigation is adaptive spatial filtering. We study the effect of spatial…

Astrophysics · Physics 2014-10-13 Amir Leshem , Alle-Jan van der Veen

In astronomical and cosmological studies one often wishes to infer some properties of an infinite-dimensional field indexed within a finite-dimensional metric space given only a finite collection of noisy observational data. Bayesian…

Instrumentation and Methods for Astrophysics · Physics 2014-06-26 Ewan Cameron

In this work, we reconstruct the Hubble diagram using various data sets, including correlated ones, in Artificial Neural Networks (ANN). Using ReFANN, that was built for data sets with independent uncertainties, we expand it to include…

General Relativity and Quantum Cosmology · Physics 2023-11-01 Konstantinos F. Dialektopoulos , Purba Mukherjee , Jackson Levi Said , Jurgen Mifsud

The large-scale structure in cosmology is highly non-Gaussian at late times and small length scales, making it difficult to describe analytically. Parameter inference, data reconstruction, and data generation tasks in cosmology are greatly…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-13 Adam Rouhiainen

Cosmological random fields are often analysed in spherical Fourier-Bessel basis. Compared to the Cartesian Fourier basis this has an advantage of properly taking into account some of the relevant physical processes (redshift-space…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-17 Lado Samushia

The complexity and accuracy of current and future precision cosmology observational campaigns has made it essential to develop an efficient technique for directly combining simulation and observational datasets to determine cosmological and…

Astrophysics · Physics 2009-11-11 Katrin Heitmann , David Higdon , Charles Nakhleh , Salman Habib

This paper introduces a new approach to reconstruct cosmological functions using artificial neural networks based on observational measurements with minimal theoretical and statistical assumptions. By using neural networks, we can generate…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-24 Isidro Gómez-Vargas , Ricardo Medel Esquivel , Ricardo García-Salcedo , J. Alberto Vázquez

In this work we present a nonparametric approach, which works on minimal assumptions, to reconstruct the cosmic expansion of the Universe. We propose to combine a locally weighted scatterplot smoothing method and a simulation-extrapolation…

Cosmology and Nongalactic Astrophysics · Physics 2014-02-20 Ariadna Montiel , Ruth Lazkoz , Irene Sendra , Celia Escamilla-Rivera , Vincenzo Salzano

Circumstellar disks play a key role in the understanding of stellar systems. Direct imaging of such extended structures is a challenging task. Current post-processing techniques, first tailored for exoplanets imaging, tend to produce…

Instrumentation and Methods for Astrophysics · Physics 2019-02-27 Benoît Pairet , Faustine Cantalloube , Laurent Jacques
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