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Related papers: Data augmentation for galaxy density map reconstru…

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Data augmentation refers to the process of applying a series of transformations or expansions to original data to generate new samples, thereby increasing the diversity and quantity of the data, effectively improving the performance and…

Computer Vision and Pattern Recognition · Computer Science 2024-06-11 Hao Zhang , Shuaijie Zhang , Renbin Zou

Owing to their more extensive sky coverage and tighter control on systematic errors, future deep weak lensing surveys should provide a better statistical picture of the dark matter clustering beyond the level of the power spectrum. In this…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Dipak Munshi , Joseph Smidt , Alan Heavens , Peter Coles , Asantha Cooray

Intensity mapping has been attracting increasing interest as a way to study galaxy evolution and the large scale structure of the Universe. Instead of detecting individual galaxies, we measure the integrated emission from a volume of the…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-13 José Fonseca

We show that dust absorption in disk galaxies leads to a color- and orientation-dependent centroid shift which is expected to be observable in multi-band imaging surveys. This centroid shift is an interesting new probe which contains…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Petchara Pattarakijwanich , Fabian Schmidt

Beyond the linear regime, the power spectrum and higher order moments of the matter field no longer capture all cosmological information encoded in density fluctuations. While non-linear transforms have been proposed to extract this…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Julien Carron , Istvan Szapudi

Gravitational lensing has now become a popular tool to measure the mass distribution of structures in the Universe on various scales. Here we focus on the study of galaxy's scale dark matter halos with galaxy-galaxy lensing techniques:…

Astrophysics · Physics 2007-05-23 M. Limousin , J-P. Kneib , P. Natarajan

We explore the stability of the variance and skewness of the cosmic gravitational convergence field, using two different approaches: first we simulate a whole MEGACAM survey (100 sq. degrees). The reconstructed mass map, obtained from a…

Astrophysics · Physics 2007-05-23 A. Thion , Y. Mellier , F. Bernardeau , E. Bertin , T. Erben , L. van Waerbeke

In this paper we introduce three methods for re-scaling data sets aiming at improving the likelihood of clustering validity indexes to return the true number of spherical Gaussian clusters with additional noise features. Our method obtains…

Machine Learning · Statistics 2016-02-24 Renato Cordeiro de Amorim , Christian Hennig

Perturbative quantities, such as the growth rate ($f$) and index ($\gamma$), are powerful tools to distinguish different dark energy models or modified gravity theories even if they produce the same cosmic expansion history. In this work,…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-27 J. E. Gonzalez , J. S. Alcaniz , J. C. Carvalho

Estimating stellar masses for billions of galaxies in upcoming surveys requires methods that are both accurate and computationally efficient. We present a new approach using symbolic regression trained on a simulation to derive simple,…

A new method for measuring gravitational lensing with high redshift type Ia supernovae is investigated. The method utilizes correlations between foreground galaxies and supernova brightnesses to substantially reduce possible systematic…

Astrophysics · Physics 2017-03-22 R. Benton Metcalf

We quantify the performance of mass mapping techniques on mock imaging and gravitational lensing data of galaxy clusters. The optimum method depends upon the scientific goal. We assess measurements of clusters' radial density profiles,…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-29 Sut-Ieng Tam , Richard Massey , Mathilde Jauzac , Andrew Robertson

Accurately reconstructing a global spatial field from sparse data has been a longstanding problem in several domains, such as Earth Sciences and Fluid Dynamics. Historically, scientists have approached this problem by employing complex…

Computer Vision and Pattern Recognition · Computer Science 2024-08-23 Robert Sunderhaft , Logan Frank , Jim Davis

We present a non-parametric model for inferring the three-dimensional (3D) distribution of dust density in the Milky Way. Our approach uses the extinction measured towards stars at different locations in the Galaxy at approximately known…

Astrophysics of Galaxies · Physics 2017-03-22 S. Rezaei Kh. , C. A. L. Bailer-Jones , R. J. Hanson , M. Fouesneau

A heuristic greedy algorithm is developed for efficiently tiling spatially dense redshift surveys. In its first application to the Galaxy and Mass Assembly (GAMA) redshift survey we find it rapidly improves the spatial uniformity of our…

Extracting information from cosmic surveys is often done in a two-step process, construction of maps and then summary statistics such as two-point functions. We use simulations to demonstrate the advantages of a general Bayesian framework…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-06 Alan Junzhe Zhou , Scott Dodelson

We present a reconstructions of galaxy-cluster-scale mass distributions from simulated gravitational lensing data sets including strong lensing, weak lensing shear, and measurements of quadratic image distortions -- flexion. The lensing…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-21 Benjamin Cain , Marusa Bradac , Rebecca Levinson

Wavelets have been used extensively for several years now in astronomy for many purposes, ranging from data filtering and deconvolution, to star and galaxy detection or cosmic ray removal. More recent sparse representations such ridgelets…

Instrumentation and Methods for Astrophysics · Physics 2009-03-20 Jean-Luc Starck , Jerome Bobin

We demonstrate that accurate and precise information about the matter content of the universe can be retrieved via a simple cell count analysis of the 3D spatial distribution of galaxies. A new clustering statistic, the {\it galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-05 Julien Bel , Christian Marinoni

While galaxy cluster catalogs were compiled many decades ago, other structural elements of cosmic web are detected at definite level only in the newest works. For example, extragalactic filaments were described by velocity field and SDSS…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-19 A. V. Tugay